# Running multiple MAX31856 boards **URL:** \ **Category:** Firmware\ **Created:** [June 18, 2019, 2:43am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481 "2019-06-18T02:43:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![grahamb321](https://avatars.discourse-cdn.com/v4/letter/g/9d8465/32.png) [@grahamb321](https://community.particle.io/u/grahamb321)\ **Post date:** [June 18, 2019, 2:43am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/1 "2019-06-18T02:43:09Z")
I’m trying to read multiple MAX31856 boards. I can read one just fine, but can’t seem to get the second one to read. Here’s part of my code it’s failing setting/reading the thermocouple type. I’m using software SPI, I can’t get hardware SPI to work even with only 1 board. I get therm1 just fine, but therm2 in the switch returns Unknown They both are sharing DI,DO,CLK and therm1 is on A3 and therm2 is on A4 ```auto #include // Use software SPI: CS, DI, DO, CLK Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(14, 11, 12, 13); Adafruit_MAX31856 maxthermo2 = Adafruit_MAX31856(15, 11, 12, 13); // use hardware SPI, just pass in the CS pin //Adafruit_MAX31856 maxthermo = Adafruit_MAX31856(14); String therm1 = ""; String therm2 = ""; String storetemp1 = ""; float read1 = 0; float read2 = 0; float read3 = 0; float read4 = 0; float read5 = 0; int count = 0; void setup() { Serial.begin(115200); maxthermo.begin(); maxthermo2.begin(); maxthermo.setThermocoupleType(MAX31856_TCTYPE_K); maxthermo2.setThermocoupleType(MAX31856_TCTYPE_K); switch (maxthermo.getThermocoupleType() ) { case MAX31856_TCTYPE_B: Particle.publish("B Type", PUBLIC); break; case MAX31856_TCTYPE_E: Particle.publish("E Type", PUBLIC); break; case MAX31856_TCTYPE_J: Particle.publish("J Type", PUBLIC); break; case MAX31856_TCTYPE_K: Particle.publish("Therm1: K Type", PUBLIC); break; case MAX31856_TCTYPE_N: Particle.publish("N Type", PUBLIC); break; case MAX31856_TCTYPE_R: Particle.publish("R Type", PUBLIC); break; case MAX31856_TCTYPE_S: Particle.publish("S Type", PUBLIC); break; case MAX31856_TCTYPE_T: Particle.publish("T Type", PUBLIC); break; case MAX31856_VMODE_G8: Particle.publish("Voltage x8 Gain mode", PUBLIC); break; case MAX31856_VMODE_G32: Particle.publish("Voltage x8 Gain mode", PUBLIC); break; default: Particle.publish("Therm1: Unknown1234", PUBLIC); break; } switch (maxthermo2.getThermocoupleType() ) { case MAX31856_TCTYPE_B: Particle.publish("B Type", PUBLIC); break; case MAX31856_TCTYPE_E: Particle.publish("E Type", PUBLIC); break; case MAX31856_TCTYPE_J: Particle.publish("J Type", PUBLIC); break; case MAX31856_TCTYPE_K: Particle.publish("Therm2: K Type", PUBLIC); break; case MAX31856_TCTYPE_N: Particle.publish("N Type", PUBLIC); break; case MAX31856_TCTYPE_R: Particle.publish("R Type", PUBLIC); break; case MAX31856_TCTYPE_S: Particle.publish("S Type", PUBLIC); break; case MAX31856_TCTYPE_T: Particle.publish("T Type", PUBLIC); break; case MAX31856_VMODE_G8: Particle.publish("Voltage x8 Gain mode", PUBLIC); break; case MAX31856_VMODE_G32: Particle.publish("Voltage x8 Gain mode", PUBLIC); break; default: Particle.publish("Therm2: Unknown1234", PUBLIC); break; } Particle.variable("therm1",therm1); Particle.variable("therm2",therm2); Particle.variable("storetemp1",storetemp1); read1 = 0; read2 = 0; read3 = 0; read4 = 0; read5 = 0; count = 0; } ``` ---
**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:** [June 18, 2019, 3:47am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/2 "2019-06-18T03:47:37Z")
Are you using a Particle board? Which? Here in the Particle community we prefer using the pin _labels_ rather than anonymous pin numbers. When you tried HW SPI which code did you try? ---
**Author:** ![grahamb321](https://avatars.discourse-cdn.com/v4/letter/g/9d8465/32.png) [@grahamb321](https://community.particle.io/u/grahamb321)\ **Post date:** [June 19, 2019, 2:39am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/3 "2019-06-19T02:39:30Z")
I’m using the Adafruit MAX31856 daughter board along with a Particle Boron. When I tried hardware SPI, I just commented out the first maxthermo lines and uncommented the one under hardware SPI. I just got nan readings from what I remember. I can get one to work just fine, if I’m reading the code right doing 2 boards, I would wire the DI/DO/CLK pins from both boards in parallel and simply use 2 different pins for the CS. ---
**Author:** ![grahamb321](https://avatars.discourse-cdn.com/v4/letter/g/9d8465/32.png) [@grahamb321](https://community.particle.io/u/grahamb321)\ **Post date:** [June 19, 2019, 3:37am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/4 "2019-06-19T03:37:53Z")
Ok, I was actually able to solve this. I got Hardware SPI to work and got 2 boards reading. ---
**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:** [June 19, 2019, 10:12am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/5 "2019-06-19T10:12:51Z")
Can you tell us what you did to solve the issue? It may help others to solve similar issues for fellow members 😉 ---
**Author:** ![markwkiehl](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/markwkiehl/32/23561_2.png) [@markwkiehl](https://community.particle.io/u/markwkiehl)\ **Post date:** [February 18, 2020, 10:06am UTC](https://community.particle.io/t/running-multiple-max31856-boards/50481/6 "2020-02-18T10:06:33Z")
Follow the link to see sample code for the MAX31856 that works on the Argon / Boron. Add the library using the name “Adafruit\_MAX31856\_library”. [http://www.savvysolutions.info/savvymicrocontrollersolutions/particle.php?topic=particle-thermocouple](http://www.savvysolutions.info/savvymicrocontrollersolutions/particle.php?topic=particle-thermocouple)