Just got an Enviro Phat, a few basic questions


#1

Q1. I got an Enviro Phat at Microcenter in the USA, very excited. Strange question, but why does it say it’s only “compatible with 0 2 3 A+ B+” on the box. I’m assuming it’s because those all have a 40 pin header. I love your pinout.xyz site, so very useful. But. It says Enviro Phat uses a few pins at the top of the header, which the RPi 1 model B has. Can I use it with my RPi1 Model B? I’m running Stretch on the RPi1, so there’s no Wheezy incompatibility.

Question 2, a little embarrassing, but when I bought it, I noticed, someone had taken the 6 pin and 40 pin solder-in headers. OK, I really wanted the Enviro Phat, so Microcenter reduce the price for me, and I bought it anyway. This question is related to my Question 1. I have a few 8 pin Arduino headers. Since the Enviro Phat only uses the few pins at the top of the header can I solder those in for physical pins 1 through 16?

Quoting pinout.xyz:

  • Needs 5v power
  • Uses 3 GPIO pins
  • Communication over I2C
  • 0x49: ADS1015
  • 0x29: TCS3472
  • 0x1d: LSM303D
  • 0x77: BMP280

My 8 pin headers would go at the top, taking care of the I2C pins, 5v (and 3.3v), and two Gnd pins (at physical pins 6 and 9). I think that would cover everything, but thought I should ask.


#2

OK, so you have the 1B, not the 1B+ right? The 1B only has the 26 pin GPIO and the 1B+ has the 40. Its my understanding that the 26 PIN GPIO is not a pin for pin match to those same 26 pins on the 40 pin header. Some pins were renamed or moved. Trying to find the actual documentation is tricky. My searches keep leading me to the 40 pin layout. I’ll have another go after I get another cup of coffee, lol. I think this is the 26 pin one, http://pi.gadgetoid.com/article/raspberry-pi-gpio-pinout-guide

Yes, you can solder you short headers in only where PINs are actually used. Just pay attention to where the grounds are. If possible I’d place your headers to cover as many of those as you can. And the +5V for sure.


#3

How many 8 PIN headers do you have? If your carful, you could trim one down to just the number of pins you need to get the full 26, or even the full 40 pins covered on the enviro phat.


#4

Just found this, hop it helps
.


#5

Right, that what I planned. Just solder two 8 pin connectors to pins 1 through 16. Assuming pinout.xyz is correct, that’s enough to make it work. It covers 3 ground pins.


#6

Yes, I have several Pi 1 model B, not B+. and a Pi 3 model B, and a zero W. I want to be able to move the Enviro Phat around to all of those. (I plan to monitor the temperature in my attic, and want to use the old model 1, in case something overheats.) I’ve looked at the 26 pin and 40 pin header assignments, they look the same to me. I’ll solder it together and see how things work out.


#7

They always looked the same to me too, but people on the official Pi forum keep telling me caution is advised? Maybe it was the 40 Pin header that got a revision? I see two DNC listings in the image I posted that I assume mean Do Not Connect? That’s just a guess though as its the first time I’ve seen DNC in the pinout?


#8

I don’t have any of the 26 pin GPIO Pi’s. My first was a B+, then a 2B+.
Currently I have 2 3B’s, 2 A+'s, and a bunch of Zero W"s.
And all my Hats and pHats are 40 pin.


#9

Just found this, http://raspi.tv/2013/rpi-gpio-basics-2-how-to-check-what-pi-board-revision-you-have
And this, https://www.raspberrypi.org/forums/viewtopic.php?t=20355
Which links to this, https://elinux.org/RPi_Low-level_peripherals


#10

OK, today I got around to soldering the enviro phat. I used the 2 x 8 pin headers, and of course since the enviro phat uses only I2c (and 5v & Gnd) it worked just fine.

Loaded the software on a Pi 3B (for speed sake) and tested the weather.temperature() and leds.on(), and then moved it to a Pi ZeroW, and it worked great there too. Next step, trying it on an old Pi 1B.


#11

Nice, have fun. =)
My Pimoroni order just arrived yesterday. I now have BME680 to play with.