[challenge-bot] / pcb / index.html

								<HTML>
								<Head>
								<Title>
MBino (Rev. C)
								</Title>
								</Head>
								<Body>
								<H1>
MBino (Rev. C)
								</H1>
								<P>
								</P>
								<H2>
Table of Contents
								</H2>
								<P>
								<UL><LI>
	<A HRef="#Schematic">
    1.0 Schematic</A>
								</LI><LI>
	<A HRef="#Design_Files">
    2.0 Design Files</A>
								</LI><LI>
	<A HRef="#Errata_and_Notes">
    3.0 Errata and Notes</A>
								</LI><LI>
	<A HRef="#Bootloader">
    4.0 Bootloader</A>
								</LI><LI>
	<A HRef="#IDE">
    5.0 IDE</A>
								</LI></UL>
								</P>
								<H2>
    <A Name="Schematic">
1.0 Schematic</A>
								</H2>
								<P>
The schematic is available as either a
    <A HRef="mbino.pdf">
.pdf</A> file or as a
    <A HRef="mbino.svg">
.svg</A> (Scalable Vector Graphics) file.
The .pdf file should print reasonably well on a black
and white printer.  The .svg file is embedded below:
								</P>

    <Img Src="mbino.svg">
								<P>
There are two 2.1mm power jacks , N1 and N3.
N1 feeds power through protection diode D1 and
protection resettable polyfuse F2 to the LPWR1
and LWPR2 pins of MakeBus connector N2.  D1 protects
everthing if the power accidentally comes in with
reverse polarity on N1.  (Connector N2 is labeled as
"Robus" which is the previous bus name to "MakerBus".)
The ground line of N1 is also connected to LGND1
and LGND2 of N2.  The same thing happens with N3,
F1, and D2 with BPWR1, BPWR2, BGND1, and BGND2 on N2.
								</P><P>
The LPWR1 and LPWR1 lines from N2 are further connected
to the 5V linear regulator U1 and the 3.3V linear
regulator U2 to provide 5 volts and 3.3 volts respectively.
								</P><P>
CANH and CANL of N2 or connected to the 5V CAN bus
transceiver chip U3.  The 1 &times; 3 jumper J1 can
be jumpered to connect a 124 ohm termination resistor R6.
The 24K resistor R9 enables slope control for U3.
The TXD and RXD pins are connected to the microcontroller
U4 pins PD3 (TXD1) and PD2 (RXD1).  Capacitors C5-C10
are .1&micro;F bypass capacitors for U4 and U3.
16MHz crystal X1 and crystal 22pF capactiors C4 and C5
provide the 16MHz frequency reference for U4.
								</P><P>
Connector N4 is a 2&times;8 pin combined JTAG and
serial download connector that connects to the
various JTAG pins on the microcontroller (U4).
The serial debug lines from N4 are also connected
to the 1&times;6 serial cable pin N5 before
connecting to PD1 (TXD0) and PD0 (RXD0) on U4
through 1K ohm resistors R2 and R3.  R2 and R3
pins D0 (N9) and D1 (N9) to have priority over
over both N4 and N5 is voltage sources are connected
to both at the same time.  It is a really bad idea
to attempt to use both N4 and N5 for serial downloading
at the same time.  10K ohm resistor R1 and 1&micro;F
capacitor C12 provide a simple reset circuit to trigger
RESET on U4.  The reset button SW1 can also be used
to manually reset U4.
								</P><P>
470 Ohm resistor R8 and LED D4 are connected to D13
(N8) to provide an on-board LED.  470 ohm resistor R7
and bicolor LED D3 are only meant to be used for
debugging; they are not installed in the final product.
Connectors N6 (Power/Reset pins), N7 (ISP header),
N8 (D0-D13, GND, AREF), N9 (D0-D7) and N10 (A0-A5)
are used used to connect to Arduino compatible shields.
								</P><P>
4.7K ohm resistors R4 and R5 are available to be used
as pull up resistors for the I<Sup>2</Sup>C bus pins
connected to D13 (SCK) and D12 (MISO) pins on U4.
								</P>
								<H2>
    <A Name="Design_Files">
2.0 Design Files</A>
								</H2>
								<P>
This board was designed using KiCAD.  The design
files are kept at
    <A HRef="http://github.com/waynegramlich/mbino">
http://github.com/waynegramlich/mbino</A>.
								</P>
								<H2>
    <A Name="Errata_and_Notes">
3.0 Errata and Notes</A>
								</H2>
								<P>
The following errors and issues are noted:
								<UL><LI>
    A reset circuit for MakerBus is needed.
								</LI></UL>
								</P><P>
The design notes for the reset circuit are:
								<UL><LI>
Use a SNLVC2G06 (dual open collector inverter):
								</LI><LI>
At VCC = 5V:
								<UL><LI>
   V<Sub>IH</Sub> = .7 * V<Sub>CC</Sub> = 3.5V
								</LI><LI>
   V<Sub>IL</Sub> = .3 * V<Sub>CC</Sub> = 1.5V
								</LI><LI>
   V<Sub>OL</Sub> = .55V
								</LI><LI>
   I<Sub>OL</Sub> = 32mA
								</LI></UL>
								</LI><LI>
Assuming that the capacitor is clamped to VOL most
of the time, the R*C that corresponds to charging
from VOL to VIH in T seconds is the
the basic capacitor charging equation:
								</LI><UL><LI>
  V(t) = V<Sub>OL</Sub> + (V<Sub>CC</Sub> -
     V<Sub>OL</Sub>) * (1 - e<Sup>-t/R*C</Sup>)
								</LI></UL><LI>
Replacing V(t) with V<Sub>IH</Sub> and T:
								<UL><LI>
  V<Sub>IH</Sub> = V<Sub>OL</Sub> + (V<Sub>CC</Sub> -
    V<Sub>OL</Sub>) * (1 - e<Sup>-T/R*C</Sup>)
								</LI></UL>
								</LI><LI>
Solving for RC:
								<UL><LI>
  (V<Sub>IH</Sub> - V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>L</Sub>) = 
  1 - e<Sup>-T/R*C</Sup>
								</LI><LI>
  e<Sup>-T/R*C</Sup> = 1 - (V<Sub>IH</Sub> -
    V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>)
								</LI><LI>
  -T/R*C = ln(1 - (V<Sub>IH</Sub> -
    V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>))
								</LI><LI>
  R*C = -T/ln(1 - (V<Sub>IH</Sub> -
    V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>))
								</LI></UL>
								</LI><LI>
Substituting in for T=1mS, V<Sub>IH</Sub>,
V<Sub>OL</Sub>, and V<Sub>CC</Sub>:
								<UL><LI>
  R*C =  -.001/ln(1 - (3.5 - .55)/(5 - .55))
								</LI><LI>
  R*C = -.001/-1.08744
								</LI><LI>
  R*C = .009196
								</LI></UL>
								</LI><LI>
Setting C = .1&micro;F
								<UL><LI>
  R = .009196 / .0000001 = 9196
								</LI></UL>
Using an R near 10K should do the trick.
								</LI><LI>
The maximum discharge current is I<Sub>OL</Sub>.  Use Ohm's law
to determine determine discharge resistor:
								<UL><LI>
   V = I * R
								</LI><LI>
   R = V / I
     = 5 / .032
     = 156.25
								</LI></UL>
Setting R<Sub>discharge</Sub> = 180 should be good enough.
								</LI><LI>
The charge/discharge ratio is:
								<UL><LI>
  R<Sub>charge</Sub>/R<Sub>discharge</Sub> = 10K/180 = 55.5
								</LI></UL>
								</LI></UL>
								<P>
								<H2>
    <A Name="Bootloader">
4.0 Bootloader</A>
								</H2>
								<P>
{Bootloader discussion goes here!}
								</P>
								<H2>
    <A Name="IDE">
5.0 IDE</A>							</H2>
								<P>
The following URL specifies how to add a new board:
								<BlockQuote>

	<A HRef="http://www.avr-developers.com/corefiles/index.html">
    http://www.avr-developers.com/corefiles/index.html</A>
								</BlockQuote>
								</P><P>
The short answer is:
								<Pre>
    cd .../hardware
    (cd arduino; tar cvf /tmp/arduino.tar .)
    (mkdir {your_board_dir}; tar xvf /tmp/arduino.tar)
    # now edit {your_board_dir}/boards.txt to configure your board
    # now edit {your_board_dir}/programmers.txt
								</Pre>
The problem with this strategy is that you get a snap-shot of
all the files and everything becomes out of date when the next
release of the Arduino IDE comes out.  A better way is probably
to have a shell script that make a copy of arduino files followed
by a file that unzips the stuff that needs to be changed.  That
may be just a few files.
								</P><P>
Here are the files that have been edited so far:
								<DL><DT>
  .../MBino/variants/standard/pins_arduino.h:			</DT><DD>
								<Pre>
    // Add 4 pins to the vector for I2C SDA, SCL, and external pull-ups
    SDA = 20
    SCL = 21

    port_to_mode_PGM = {
	// Add &DDRA,	// ATmega324 has a Port A

    port_to_output_PGM = {
	// Add &PORTA,	// ATmega324 has a Port A

    port_to_input_PGM = {
	// Add &PINA,	// ATmega324 has a Port A

    digital_pin_to_port_PGM = {
	// Remap digital pin ports

    digital_pin_to_bit_mask_PGM = {
	// Remap bit masks
								</Pre>
Obviously thes is pretty minor changes.
								</DD></DL>
								</P><P>
{Create a .zip file that creates the various MBino
sub-directories for the Arduino IDE.}
								</P>
								<HR>
								<Address>
    <A HRef="http://gramlich.net/copyright.html">
Copyright</A> 2013 by
    <A HRef="http://gramlich.net/index.html">
Wayne C. Gramlich</A>.
All rights reserved.
								</Address>
								</Body>
								</HTML>
Commit	Line	Data
	1	<HTML>
	2	<Head>
	3	<Title>
	4	MBino (Rev. C)
	5	</Title>
	6	</Head>
	7	<Body>
	8	<H1>
	9	MBino (Rev. C)
	10	</H1>
	11	<P>
	12	</P>
	13	<H2>
	14	Table of Contents
	15	</H2>
	16	<P>
	17	<UL><LI>
	18	<A HRef="#Schematic">
	19	1.0 Schematic</A>
	20	</LI><LI>
	21	<A HRef="#Design_Files">
	22	2.0 Design Files</A>
	23	</LI><LI>
	24	<A HRef="#Errata_and_Notes">
	25	3.0 Errata and Notes</A>
	26	</LI><LI>
	27	<A HRef="#Bootloader">
	28	4.0 Bootloader</A>
	29	</LI><LI>
	30	<A HRef="#IDE">
	31	5.0 IDE</A>
	32	</LI></UL>
	33	</P>
	34	<H2>
	35	<A Name="Schematic">
	36	1.0 Schematic</A>
	37	</H2>
	38	<P>
	39	The schematic is available as either a
	40	<A HRef="mbino.pdf">
	41	.pdf</A> file or as a
	42	<A HRef="mbino.svg">
	43	.svg</A> (Scalable Vector Graphics) file.
	44	The .pdf file should print reasonably well on a black
	45	and white printer. The .svg file is embedded below:
	46	</P>
	47
	48	<Img Src="mbino.svg">
	49	<P>
	50	There are two 2.1mm power jacks , N1 and N3.
	51	N1 feeds power through protection diode D1 and
	52	protection resettable polyfuse F2 to the LPWR1
	53	and LWPR2 pins of MakeBus connector N2. D1 protects
	54	everthing if the power accidentally comes in with
	55	reverse polarity on N1. (Connector N2 is labeled as
	56	"Robus" which is the previous bus name to "MakerBus".)
	57	The ground line of N1 is also connected to LGND1
	58	and LGND2 of N2. The same thing happens with N3,
	59	F1, and D2 with BPWR1, BPWR2, BGND1, and BGND2 on N2.
	60	</P><P>
	61	The LPWR1 and LPWR1 lines from N2 are further connected
	62	to the 5V linear regulator U1 and the 3.3V linear
	63	regulator U2 to provide 5 volts and 3.3 volts respectively.
	64	</P><P>
	65	CANH and CANL of N2 or connected to the 5V CAN bus
	66	transceiver chip U3. The 1 × 3 jumper J1 can
	67	be jumpered to connect a 124 ohm termination resistor R6.
	68	The 24K resistor R9 enables slope control for U3.
	69	The TXD and RXD pins are connected to the microcontroller
	70	U4 pins PD3 (TXD1) and PD2 (RXD1). Capacitors C5-C10
	71	are .1µF bypass capacitors for U4 and U3.
	72	16MHz crystal X1 and crystal 22pF capactiors C4 and C5
	73	provide the 16MHz frequency reference for U4.
	74	</P><P>
	75	Connector N4 is a 2×8 pin combined JTAG and
	76	serial download connector that connects to the
	77	various JTAG pins on the microcontroller (U4).
	78	The serial debug lines from N4 are also connected
	79	to the 1×6 serial cable pin N5 before
	80	connecting to PD1 (TXD0) and PD0 (RXD0) on U4
	81	through 1K ohm resistors R2 and R3. R2 and R3
	82	pins D0 (N9) and D1 (N9) to have priority over
	83	over both N4 and N5 is voltage sources are connected
	84	to both at the same time. It is a really bad idea
	85	to attempt to use both N4 and N5 for serial downloading
	86	at the same time. 10K ohm resistor R1 and 1µF
	87	capacitor C12 provide a simple reset circuit to trigger
	88	RESET on U4. The reset button SW1 can also be used
	89	to manually reset U4.
	90	</P><P>
	91	470 Ohm resistor R8 and LED D4 are connected to D13
	92	(N8) to provide an on-board LED. 470 ohm resistor R7
	93	and bicolor LED D3 are only meant to be used for
	94	debugging; they are not installed in the final product.
	95	Connectors N6 (Power/Reset pins), N7 (ISP header),
	96	N8 (D0-D13, GND, AREF), N9 (D0-D7) and N10 (A0-A5)
	97	are used used to connect to Arduino compatible shields.
	98	</P><P>
	99	4.7K ohm resistors R4 and R5 are available to be used
	100	as pull up resistors for the I<Sup>2</Sup>C bus pins
	101	connected to D13 (SCK) and D12 (MISO) pins on U4.
	102	</P>
	103	<H2>
	104	<A Name="Design_Files">
	105	2.0 Design Files</A>
	106	</H2>
	107	<P>
	108	This board was designed using KiCAD. The design
	109	files are kept at
	110	<A HRef="http://github.com/waynegramlich/mbino">
	111	http://github.com/waynegramlich/mbino</A>.
	112	</P>
	113	<H2>
	114	<A Name="Errata_and_Notes">
	115	3.0 Errata and Notes</A>
	116	</H2>
	117	<P>
	118	The following errors and issues are noted:
	119	<UL><LI>
	120	A reset circuit for MakerBus is needed.
	121	</LI></UL>
	122	</P><P>
	123	The design notes for the reset circuit are:
	124	<UL><LI>
	125	Use a SNLVC2G06 (dual open collector inverter):
	126	</LI><LI>
	127	At VCC = 5V:
	128	<UL><LI>
	129	V<Sub>IH</Sub> = .7 * V<Sub>CC</Sub> = 3.5V
	130	</LI><LI>
	131	V<Sub>IL</Sub> = .3 * V<Sub>CC</Sub> = 1.5V
	132	</LI><LI>
	133	V<Sub>OL</Sub> = .55V
	134	</LI><LI>
	135	I<Sub>OL</Sub> = 32mA
	136	</LI></UL>
	137	</LI><LI>
	138	Assuming that the capacitor is clamped to VOL most
	139	of the time, the R*C that corresponds to charging
	140	from VOL to VIH in T seconds is the
	141	the basic capacitor charging equation:
	142	</LI><UL><LI>
	143	V(t) = V<Sub>OL</Sub> + (V<Sub>CC</Sub> -
	144	V<Sub>OL</Sub>) * (1 - e<Sup>-t/R*C</Sup>)
	145	</LI></UL><LI>
	146	Replacing V(t) with V<Sub>IH</Sub> and T:
	147	<UL><LI>
	148	V<Sub>IH</Sub> = V<Sub>OL</Sub> + (V<Sub>CC</Sub> -
	149	V<Sub>OL</Sub>) * (1 - e<Sup>-T/R*C</Sup>)
	150	</LI></UL>
	151	</LI><LI>
	152	Solving for RC:
	153	<UL><LI>
	154	(V<Sub>IH</Sub> - V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>L</Sub>) =
	155	1 - e<Sup>-T/R*C</Sup>
	156	</LI><LI>
	157	e<Sup>-T/R*C</Sup> = 1 - (V<Sub>IH</Sub> -
	158	V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>)
	159	</LI><LI>
	160	-T/R*C = ln(1 - (V<Sub>IH</Sub> -
	161	V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>))
	162	</LI><LI>
	163	R*C = -T/ln(1 - (V<Sub>IH</Sub> -
	164	V<Sub>OL</Sub>)/(V<Sub>CC</Sub> - V<Sub>OL</Sub>))
	165	</LI></UL>
	166	</LI><LI>
	167	Substituting in for T=1mS, V<Sub>IH</Sub>,
	168	V<Sub>OL</Sub>, and V<Sub>CC</Sub>:
	169	<UL><LI>
	170	R*C = -.001/ln(1 - (3.5 - .55)/(5 - .55))
	171	</LI><LI>
	172	R*C = -.001/-1.08744
	173	</LI><LI>
	174	R*C = .009196
	175	</LI></UL>
	176	</LI><LI>
	177	Setting C = .1µF
	178	<UL><LI>
	179	R = .009196 / .0000001 = 9196
	180	</LI></UL>
	181	Using an R near 10K should do the trick.
	182	</LI><LI>
	183	The maximum discharge current is I<Sub>OL</Sub>. Use Ohm's law
	184	to determine determine discharge resistor:
	185	<UL><LI>
	186	V = I * R
	187	</LI><LI>
	188	R = V / I
	189	= 5 / .032
	190	= 156.25
	191	</LI></UL>
	192	Setting R<Sub>discharge</Sub> = 180 should be good enough.
	193	</LI><LI>
	194	The charge/discharge ratio is:
	195	<UL><LI>
	196	R<Sub>charge</Sub>/R<Sub>discharge</Sub> = 10K/180 = 55.5
	197	</LI></UL>
	198	</LI></UL>
	199	<P>
	200	<H2>
	201	<A Name="Bootloader">
	202	4.0 Bootloader</A>
	203	</H2>
	204	<P>
	205	{Bootloader discussion goes here!}
	206	</P>
	207	<H2>
	208	<A Name="IDE">
	209	5.0 IDE</A> </H2>
	210	<P>
	211	The following URL specifies how to add a new board:
	212	<BlockQuote>
	213
	214	<A HRef="http://www.avr-developers.com/corefiles/index.html">
	215	http://www.avr-developers.com/corefiles/index.html</A>
	216	</BlockQuote>
	217	</P><P>
	218	The short answer is:
	219	<Pre>
	220	cd .../hardware
	221	(cd arduino; tar cvf /tmp/arduino.tar .)
	222	(mkdir {your_board_dir}; tar xvf /tmp/arduino.tar)
	223	# now edit {your_board_dir}/boards.txt to configure your board
	224	# now edit {your_board_dir}/programmers.txt
	225	</Pre>
	226	The problem with this strategy is that you get a snap-shot of
	227	all the files and everything becomes out of date when the next
	228	release of the Arduino IDE comes out. A better way is probably
	229	to have a shell script that make a copy of arduino files followed
	230	by a file that unzips the stuff that needs to be changed. That
	231	may be just a few files.
	232	</P><P>
	233	Here are the files that have been edited so far:
	234	<DL><DT>
	235	.../MBino/variants/standard/pins_arduino.h: </DT><DD>
	236	<Pre>
	237	// Add 4 pins to the vector for I2C SDA, SCL, and external pull-ups
	238	SDA = 20
	239	SCL = 21
	240
	241	port_to_mode_PGM = {
	242	// Add &DDRA, // ATmega324 has a Port A
	243
	244	port_to_output_PGM = {
	245	// Add &PORTA, // ATmega324 has a Port A
	246
	247	port_to_input_PGM = {
	248	// Add &PINA, // ATmega324 has a Port A
	249
	250	digital_pin_to_port_PGM = {
	251	// Remap digital pin ports
	252
	253	digital_pin_to_bit_mask_PGM = {
	254	// Remap bit masks
	255	</Pre>
	256	Obviously thes is pretty minor changes.
	257	</DD></DL>
	258	</P><P>
	259	{Create a .zip file that creates the various MBino
	260	sub-directories for the Arduino IDE.}
	261	</P>
	262	<HR>
	263	<Address>
	264	<A HRef="http://gramlich.net/copyright.html">
	265	Copyright</A> 2013 by
	266	<A HRef="http://gramlich.net/index.html">
	267	Wayne C. Gramlich</A>.
	268	All rights reserved.
	269	</Address>
	270	</Body>
	271	</HTML>