# SPI on Particle Photon **URL:** \ **Category:** Firmware\ **Created:** [November 10, 2017, 4:50pm UTC](https://community.particle.io/t/spi-on-particle-photon/37380 "2017-11-10T16:50:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![ymki](https://avatars.discourse-cdn.com/v4/letter/y/a5b964/32.png) [@ymki](https://community.particle.io/u/ymki)\ **Post date:** [November 10, 2017, 4:50pm UTC](https://community.particle.io/t/spi-on-particle-photon/37380/1 "2017-11-10T16:50:23Z")
I asked a similar question last week - [PT100 MAX31865 Temperature Sensor](https://community.particle.io/t/pt100-max31865-temperature-sensor/37313/4) - although now I have narrowed down the problem to a more specific topic. Still using this library - [https://github.com/adafruit/Adafruit\_MAX31865](https://github.com/adafruit/Adafruit_MAX31865) Last week, I was trying to get an RTD temperature sensor to work with a Particle Photon’s SPI spins - I used both the device itself and also with a Shield that is supposed to let it have an Arduino’s same outputs. Both of which didn’t work; I would still get an RTD value of 0. However, today I borrowed an Arduino to test it on. Same set-up, did not change the RTD breakout board or anything. When I ran the code in Arduino, it worked! --So that means the problem seems to be the Particle Photon or possibly its SPI channels. Why wouldn’t this work with the Shield (I used 10 - 13 there.) Are A2 - A5 the incorrect pins to use for SPI? When I checked the chart, they seemed to be correct: ![](https://us1.discourse-cdn.com/flex026/uploads/particle/original/2X/b/b9edcbfd1e0e298f1f987bcc4b496f2146f2a86f.png) Or should I be using some other pins? ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [November 10, 2017, 5:01pm UTC](https://community.particle.io/t/spi-on-particle-photon/37380/2 "2017-11-10T17:01:04Z")
A post was merged into an existing topic: [PT100 MAX31865 Temperature Sensor](https://community.particle.io/t/pt100-max31865-temperature-sensor/37313) There is no point in opening a new thread for the same issue, so I moved that post back to the original thread. ---
**Author:** ![ScruffR](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/scruffr/32/6952_2.png) [@ScruffR](https://community.particle.io/u/ScruffR)\ **Post date:** [November 10, 2017, 5:01pm UTC](https://community.particle.io/t/spi-on-particle-photon/37380/3 "2017-11-10T17:01:04Z")