LoPy pinout (work in progress)

[Xykon]

I've been trying to figure out the physical pinout of the LoPy as I couldn't wait for this to be officially released.

Here is how far I got. If anyone has any info on the remaining pins please share. I've got a busy weekend ahead so not sure when I'll get back to this.

The good news is that the JTAG pins are available on the header so finding the remaining pins shouldn't be as difficult.

You can find the Excel file here

[Xykon]

@bartvandeenen said in LoPy pinout (work in progress):

I plan to build an open-source wireless house thermostat

Wouldn't a thermostat chip like the DS1620 be easier in this case?

[bartvandeenen]

@mfgeorge
No there's nothing yet. I'll post here in the forum when there's something.

[mfgeorge]

@bartvandeenen Good to hear I could help you out! Do you already have your source code on github? I am interested to see how your project will turn out, software and hardware wise.

[bartvandeenen]

@mfgeorge said in LoPy pinout (work in progress):

Hello all,

I have found the i2c pins for bus 0 (currently the only one that does not throw an OSError during instantiation).

P9 - SDA Bus 0
P10- SCL Bus 0

Again this is presumably for i2c bus 0. ie i2c_object = I2C(0, I2C.MASTER)

Method for finding these pins:

These pins were found by looping a "while True: i2c.scan()" in the REPL prompt and scoping around for a clock signal. After the clock signal was found I continued the i2c.scan() and plugged in an i2c sensors SCL to the P10, and checked to either side with the sensors SDA pin and found the address for the sensor was reported back while SDA was connected on P9.

Hope this helps and happy hacking everyone!

I can confirm, these pins worked right away. I'm using a TMP102 thermometer on address 73d, and I can read the temperature with a oneliner:

struct.unpack(">H", i2c.readfrom(TMP,2))[0] * 0.0625/16.
28.25

Thanks.

P.S. I plan to build an open-source wireless house thermostat with the UI on a smartphone, connecting via ble or a lorawan gateway. I choose this board because of its integration and low power consumption. The micropython is a very nice bonus, I was expecting to jump back into C and assembly :-)

[pighixxx]

RTW version

[pighixxx]

@bmarkus said in LoPy pinout (work in progress):

Is P24 (3.3V) input only? I think when board powered from VIN/5V it can be used to power 3.3V external devices.

https://forum.pycom.io/topic/62/3-3v-output-max-load-current

No, I put also a note that the LDO have a 1.2A load capability.

[Xykon]

@bmarkus said in LoPy pinout (work in progress):

Is P24 (3.3V) input only? I think when board powered from VIN/5V it can be used to power 3.3V external devices.

P24 is not an IO pin... it's either 3.3V input if you want to power your LoPy from a stable 3.3V power source or it's 3.3V output from the regulator that transforms VIN to 3.3V.

[bmarkus]

Is P24 (3.3V) input only? I think when board powered from VIN/5V it can be used to power 3.3V external devices.

https://forum.pycom.io/topic/62/3-3v-output-max-load-current

[pighixxx]

@Xykon Yes, up to 16 channels simultaneously

[profra]

@pighixxx oops, probably some misunderstanding, I can not find it... I mean Pymakr and WiPy 2 pins

[Xykon]

@livius said in LoPy pinout (work in progress):

nice but all pins are PWM?

I'd rather say all pins can be assigned to one of the 8 high or low speed PWMs.

[livius]

nice but all pins are PWM?

[pighixxx]

This is the revised version:

[pighixxx]

Is the Expansion Board

[profra]

@pighixxx I guess you mean Pymakr = LoPy?

[pighixxx]

Hi,

Today i release the WiPy and Pymakr pinouts then I make the changes to WyPy pinout in the next revision.

[LoneTech]

@pighixxx Thanks! I'd like some small additions if possible.

1. Which level to use to select internal antenna
2. Bootstrapping pins:
   2a. P2 for the low level bootloader, must not be grounded for normal bootup
   2b. P12 for the multiboot / safemode, which should not be kept high for normal MicroPython use

I haven't dug around for the capacitive touch features, but I'd have expected that SensVN and SensVP formed one pair, and SensCN and SensCP would form another. Still much to learn.

[pighixxx]

Hi all,

Today i released the official LoPy pinout:

Download the PDF here

Have a noce day!

[Xykon]

@mfgeorge It looks like the DFRobot FTDI breakout board I was using to test UART1 has RXI and TXD inverted. I compared it to the Sparkfun FTDI breakout I was using for UART0 and it has the RXI and TXD the other way around.

Lesson learned: Never trust the silkscreen on cheap breakout boards. I will update the graphic tomorrow.