Playing with Teensy Micromod and looking at Main and Function boards.

Note I created a related thread over on PJRC: https://forum.pjrc.com/threads/69855-Mi … ion-Boards

It has been fun playing with the Micromod, with my own breakout board.

But, those connectors have pads that my 10 left thumbs and two older eyes have difficulties soldering. So I ordered a partially assembled board, which is working pretty well.

But when Sparkfun came out with the Main Boards and function boards, I wondered if it might make sense to try it out and see how much of the functionality of my current breakout

board would be handled directly by the Main board and if I could then move all of my additional stuff onto a function board (or maybe 2)…

So for the heck of it I ordered a single main board and one of their function boards (ESP32 for wifi…)

And now to figure out how things Map. One of the first things I noticed when I looked at the schematic of the single and double main boards is that they do not breakout all of the pins of the processor boards. And not all of the pins that are brought out, go to both boards… And I need to be careful on some of the pins reverse. That is MISO->MOSI RX->TX…

If I converted the information correctly, I believe this works out something like:

F Pin	Function name	F0 Teensy pin	F1 Teensy Pin
73	3.3V		
38	A0	14	15
41	CAN-RX	30	NC
43	CAN-TX	31	NC
18	CTS	(Teensy NC)	NC
36	EEPROM_A0	0v	3.3v
34	EEPROM_A1	0v	0v
32	EEPROM_A2	0v	0v
40	EEPROM_WP		
47	F0/!INT!	4	5
49	F1/!CS!	10	39
51	F2/PWM	3	2
53	F3	40	J9
55	F4	41	J11
57	F5	42	9
59	F6	43	37
61	F7	44 (SD CS)	36
1	GND		
23	I2C_!INT!	29	29
21	I2C_SCL	19	19
19	I2C_SDA	18	18
71	PWR_EN		
16	RTS	(Teensy NC)	NC
15	RX	1	17
3	SPI_SCK	13	13
5	SPI_SDI	11	11
7	SPI_SDO	12	12
13	TX	0	16
35	USBHOST_D+	USB Host D+	NC
37	USBHOST_D-	D-	NC
70	USB_VIN	NC	NC
72	VCC

Note the F0 and F1 pin numbers here are what I think are the matching Teensy Arduino pin numbers connected

to each of these logical pins on the Function board.

Things I noticed so far include:

a) They do not bring out all of the pins needed to do SD with SDIO, and the main board has a normal SPI SD Card

b) They did not bring out the Audio pins

c) USB Host - They did bring the USB Host pins to the F0 board (not F1). BUT they did not supply anything other than 3.3V to the function board. Likewise I don’t see any connectors (other than internal to USB) where they expose the +5v from the USB connector, other than maybe some test point. So not sure how to handle that.

So now trying to decide if it is worthwhile to try laying out a card.

Note: My board shown in picture is setup to plug in either ILI9341 displays like PJRC and Ebay sell (ILI9488 on ebay has same wiring).

2nd display connector allows for several of the Adafruit displays.

Plus has setup for Dynamixel servos where I bring in 12v (3s Lipo). Note: the standard Micromod pin of VIN/3 won’t allow for this voltage. Also the board has a DC/DC converter (not populated on this page… So not sure yet how I would power the function /main board from the lipo. Only through USB3 connector?

Main thing having some fun. Now back to playing

This is good info - thanks for sharing!

Definitely good info @KurtE but a bit disappointing to say the least. Kind of limits you what expansion boards you would like to design. I had a couple in mind but this makes it a bit more difficult to implement.