Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Improve thermistor 20-21 descriptions re: ADC Vref and INA826 PT100 supply V #19246

Merged
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 4 additions & 2 deletions Marlin/Configuration.h
Original file line number Diff line number Diff line change
Expand Up @@ -375,8 +375,10 @@
* 13 : 100k Hisens 3950 1% up to 300°C for hotend "Simple ONE " & "Hotend "All In ONE"
* 15 : 100k thermistor calibration for JGAurora A5 hotend
* 18 : ATC Semitec 204GT-2 (4.7k pullup) Dagoma.Fr - MKS_Base_DKU001327
* 20 : Pt100 with circuit in the Ultimainboard V2.x with 5v excitation (AVR)
* 21 : Pt100 with circuit in the Ultimainboard V2.x with 3.3v excitation (STM32 \ LPC176x....)
* 20 : Pt100 with circuit in the Ultimainboard V2.x with mainboard ADC reference voltage = INA826 amplifier-board supply voltage.
* NOTES: (1) Must use an ADC input with no pullup. (2) Some INA826 amplifiers are unreliable at 3.3V so consider using sensor 147, 110, or 21.
* 21 : Pt100 with circuit in the Ultimainboard V2.x with 3.3v ADC reference voltage (STM32, LPC176x....) and 5V INA826 amplifier board supply.
* NOTE: ADC pins are not 5V tolerant. Not recommended because it's possible to damage the CPU by going over 500°C.
* 22 : 100k (hotend) with 4.7k pullup to 3.3V and 220R to analog input (as in GTM32 Pro vB)
* 23 : 100k (bed) with 4.7k pullup to 3.3v and 220R to analog input (as in GTM32 Pro vB)
* 30 : Kis3d Silicone heating mat 200W/300W with 6mm precision cast plate (EN AW 5083) NTC100K / B3950 (4.7k pullup)
Expand Down
3 changes: 2 additions & 1 deletion Marlin/src/module/thermistor/thermistor_21.h
Original file line number Diff line number Diff line change
Expand Up @@ -26,7 +26,8 @@
#undef OV_SCALE
#define OV_SCALE(N) (float((N) * 5) / 3.3f)

// Pt100 with INA826 amp with 3.3v excitation based on "Pt100 with INA826 amp on Ultimaker v2.0 electronics"
// Pt100 with INA826 amplifier board with 5v supply based on Thermistor 20, with 3v3 ADC reference on the mainboard.
// If the ADC reference and INA826 board supply voltage are identical, Thermistor 20 instead.
const temp_entry_t temptable_21[] PROGMEM = {
{ OV( 0), 0 },
{ OV(227), 1 },
Expand Down