For anyone using E3D_PT100_EXTRUDER_WITH_AMP as your hotend thermistor.

[5jvm0u4]

Since I found out that the built in thermistor type "PT100 INA826" is really inaccruate, I handcrafted one out of Marlin's thermistor type 247 as define in Prusa's firmware.

#if defined(E3D_PT100_EXTRUDER_WITH_AMP)
#define TEMP_SENSOR_0 247

Here's the codes you need to copy into your printer.cfg

[adc_temperature E3D_PT100_EXTRUDER_WITH_AMP]
temperature1: 0
voltage1: 0
temperature2: 1
voltage2: 1.178
temperature3: 10
voltage3: 1.217
temperature4: 20
voltage4: 1.266
temperature5: 30
voltage5: 1.305
temperature6: 40
voltage6: 1.344
temperature7: 50
voltage7: 1.383
temperature8: 60
voltage8: 1.422
temperature9: 70
voltage9: 1.461
temperature10: 80
voltage10: 1.500
temperature11: 90
voltage11: 1.540
temperature12: 100
voltage12: 1.579
temperature13: 110
voltage13: 1.618
temperature14: 120
voltage14: 1.662
temperature15: 130
voltage15: 1.701
temperature16: 140
voltage16: 1.730
temperature17: 150
voltage17: 1.760
temperature18: 160
voltage18: 1.808
temperature19: 170
voltage19: 1.848
temperature20: 180
voltage20: 1.887
temperature21: 190
voltage21: 1.926
temperature22: 200
voltage22: 1.965
temperature23: 210
voltage23: 2.004
temperature24: 220
voltage24: 2.043
temperature25: 230
voltage25: 2.082
temperature26: 240
voltage26: 2.111
temperature27: 250
voltage27: 2.151
temperature28: 260
voltage28: 2.190
temperature29: 270
voltage29: 2.219
temperature30: 280
voltage30: 2.258
temperature31: 290
voltage31: 2.292
temperature32: 300
voltage32: 2.322
temperature33: 310
voltage33: 2.361
temperature34: 320
voltage34: 2.400
temperature35: 330
voltage35: 2.439
temperature36: 340
voltage36: 2.468
temperature37: 350
voltage37: 2.507

and here's how you define your extruder in einsy-rambo.cfg

[extruder]
nozzle_diameter: 0.400
filament_diameter: 1.750
heater_pin: PE5
sensor_type: E3D_PT100_EXTRUDER_WITH_AMP
sensor_pin: PF0
min_temp: 0
max_temp: 350

just for reference, here's Marlin's thermistor table

#if (THERMISTORHEATER_0 == 247) || (THERMISTORHEATER_1 == 247) || (THERMISTORHEATER_2 == 247) || (THERMISTORBED == 247) // Pt100 with 4k7 MiniRambo pullup & PT100 Amplifier
const short temptable_247[][2] PROGMEM = {
// Calculated from Bob-the-Kuhn's PT100 calculator listed in https://github.com/MarlinFirmware/Marlin/issues/5543
// and the table provided by E3D at http://wiki.e3d-online.com/wiki/E3D_PT100_Amplifier_Documentation#Output_Characteristics.
{  0 * OVERSAMPLENR,    0},
{241 * OVERSAMPLENR,    1},
{249 * OVERSAMPLENR,   10},
{259 * OVERSAMPLENR,   20},
{267 * OVERSAMPLENR,   30},
{275 * OVERSAMPLENR,   40},
{283 * OVERSAMPLENR,   50},
{291 * OVERSAMPLENR,   60},
{299 * OVERSAMPLENR,   70},
{307 * OVERSAMPLENR,   80},
{315 * OVERSAMPLENR,   90},
{323 * OVERSAMPLENR,  100},
{331 * OVERSAMPLENR,  110},
{340 * OVERSAMPLENR,  120},
{348 * OVERSAMPLENR,  130},
{354 * OVERSAMPLENR,  140},
{362 * OVERSAMPLENR,  150},
{370 * OVERSAMPLENR,  160},
{378 * OVERSAMPLENR,  170},
{386 * OVERSAMPLENR,  180},
{394 * OVERSAMPLENR,  190},
{402 * OVERSAMPLENR,  200},
{410 * OVERSAMPLENR,  210},
{418 * OVERSAMPLENR,  220},
{426 * OVERSAMPLENR,  230},
{432 * OVERSAMPLENR,  240},
{440 * OVERSAMPLENR,  250},
{448 * OVERSAMPLENR,  260},
{454 * OVERSAMPLENR,  270},
{462 * OVERSAMPLENR,  280},
{469 * OVERSAMPLENR,  290},
{475 * OVERSAMPLENR,  300},
{483 * OVERSAMPLENR,  310},
{491 * OVERSAMPLENR,  320},
{499 * OVERSAMPLENR,  330},
{505 * OVERSAMPLENR,  340},
{513 * OVERSAMPLENR,  350},
{519 * OVERSAMPLENR,  360},
{527 * OVERSAMPLENR,  370},
{533 * OVERSAMPLENR,  380},
{541 * OVERSAMPLENR,  390},
{549 * OVERSAMPLENR,  400},
{616 * OVERSAMPLENR,  500},
{682 * OVERSAMPLENR,  600},
{741 * OVERSAMPLENR,  700},
{801 * OVERSAMPLENR,  800},
{856 * OVERSAMPLENR,  900},
{910 * OVERSAMPLENR, 1000},
{960 * OVERSAMPLENR, 1100},
};
#endif

For anyone wants to read this, the first number is the analogRead value, the last number is the corresponding temperature, I have no idea what OVERSAMPLENR does but it seems to be not affecting anything here.
The way I make that table is to work out what voltage it is at that analogRead value.

[confuzled-dev]

Does this really need to be in printer.cfg or can it not also just be defined in einsy.cfg prior to the extruder section

[dz0ny]

You can add it to printer.cfg or custom file and then include it.

[confuzled-dev]

id be interested to see some AB tests and maybe some FLIR shots

[5jvm0u4]

I'd be interested too.