Ebb42_MAX31865 and PT1000

I have installed the Goliath so i need to set up the max31865 on my ebb42 toolboard for the pt1000 thermistor, but i have tried everything and still get this error. Can you suggest me a solution, what i have missed?
20 Replies
miklschmidt
miklschmidt2y ago
I recommend using the PT1000 as a regular thermistor then all you need is:
[extruder]
sensor_type: PT1000
[extruder]
sensor_type: PT1000
and you're done.
MightyMini
MightyMini2y ago
I couldn't get the MAX running either. Same error as you. Do you have RatOS2 installed or are you still running on 1.x? Was hoping that maybe it will work with 2.0, but I haven't tried it till now. Wanted to use the pt1000 for the Hotend and the normal thermocouple as a sensor for the extruder stepper. Ended up starting to design my own board featuring more sensors. I think the ebb boards are somehow faulty, because I haven't found anyone who got it running
miklschmidt
miklschmidt2y ago
You can try software spi (usually a fix in these cases). Remove spi_bus and add:
spi_software_sclk_pin: PA5
spi_software_mosi_pin: PA7
spi_software_miso_pin: PA6
spi_software_sclk_pin: PA5
spi_software_mosi_pin: PA7
spi_software_miso_pin: PA6
Also make sure you wire it correctly (using the two middle pins in the 4 pin PT100/PT1000 connector) When using PT1000 as a thermistor (not with MAX31865) it's recommended to put the PT1000 jumper in and add:
[extruder]
pullup_resistor: 2200
[extruder]
pullup_resistor: 2200
MightyMini
MightyMini2y ago
I also tried software spi, but it didn't work. Ruled out a faulty pt1000 with using a 1k ohm resistor. Traces on the pcb are connected correctly to the MAX and the dip switches are also correct. What I didn't check was if the traces between the stm32 and the MAX are good and connected correctly. Think my scope can sniff spi protocol too, but never used that function before. I would need at least 2 temp sensors on the tool head, so only using the one single thermistor input is no solution for me. The stm32 would have 2 oder 3 more possible inputs, but BTT decided to use those ports otherwise, so no chance in "quick" hardware hacking
auggie
auggie2y ago
sorry to hijack this thread but when you say "put the PT1000 jumper in", which board are you referring to ? Octopus Pro?
MightyMini
MightyMini2y ago
we are talking about the EBB boards. You can connect a PT1000 to a normal thermistor-port, if it has a specific jumper to alter the reference resistor. If you then also change the setup and tell clipper, that there is now a PT1000, it'll work.
miklschmidt
miklschmidt2y ago
You don't need a jumper to change resistance, it just corrects the temperature offset a bit. It'll still work in a normal thermistor port.
auggie
auggie2y ago
So I am using this under [extruder] sensor_type: PT1000 pullup_resistor: 2200
auggie
auggie2y ago
but I am getting this in room temperature
No description
auggie
auggie2y ago
and the temperature is slowly dropping
miklschmidt
miklschmidt2y ago
Octopus Pro is not using a 2200 ohm pullup, that's why your temp is wrong, remove that line.
auggie
auggie2y ago
i am using ebb36
miklschmidt
miklschmidt2y ago
then you need to insert the PT1000 jumper
auggie
auggie2y ago
[extruder] pressure_advance: 0.020 max_extrude_only_distance: 200 nozzle_diameter: 0.4 heater_pin: e_heater_pin sensor_type: PT1000 pullup_resistor: 2200 sensor_pin: toolboard:e_sensor_pin min_extrude_temp: 170 min_temp: 0 max_temp: 350 pressure_advance: 0.02 with jumper on
miklschmidt
miklschmidt2y ago
Also this goes down in your user override section All modifications you make go in # User overrides
auggie
auggie2y ago
yeap it's in my override section
miklschmidt
miklschmidt2y ago
Are you sure it's a PT1000 then?
auggie
auggie2y ago
yes I am using Goliath hotend i have been scratching my head at this for the last day
miklschmidt
miklschmidt2y ago
Its most likely a wiring issue, there's no other way to explain it. Unless you're overriding your own override in your config.
auggie
auggie2y ago
i just measured the resistance across my pt1000 it's show around 1.3kohm, which is way off for room temperature i am guessing faulty pt1000 on closer inspection, found the problem, the wire was about to break
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