d1638154a6
Merge Earth and GND nets
2021-01-07 00:02:41 +01:00
aeb30f0e8b
Change 5V regulator to cheaper type
2020-12-06 20:18:50 +01:00
c8b7802314
v1.3 finished preliminary layout
2020-12-05 18:58:28 +01:00
c932da7d41
First draft of v1.3 schematic and layout
2020-11-27 22:22:05 +01:00
a0e6691255
Schematic finished for v1.3
2020-11-23 18:05:27 +01:00
07e0ea3191
Change schematic for v1.3
...
* Use DCDC buck converter for digital 3V3 supply.
* Add shielding for OPAmp section
* Change frontend amplifier to an instrumentation amplifier design
2020-11-17 18:59:20 +01:00
be3c30d734
Rescue symbol
2020-11-08 19:58:10 +01:00
e6905a50d2
remove onewire Temp sensor
2020-07-05 18:24:38 +02:00
c7b61d2e06
remove selectable voltage level for level shifter on LCB bus. This does not work
2020-02-18 20:12:22 +01:00
f1897d8342
Improve schematic and corresponding layout
2020-02-16 00:10:01 +01:00
20780781e9
Replace all MCP6V31U with MCP6V34. It's cheaper.
2020-02-06 19:49:54 +01:00
fa6782c21d
Prepare for v1.2
...
* Remove voltage buffer Opamp after TL431PK because it may oscillate
* Replace TL431PK with TL431LI. Stabilized by very large capacitance (> 10uF)
* Add panic passives to differential amplifier in order to avoid oscillaton. Values as they are now should work.
* Remove external ADC. Tests with version v1.1 show that the precision of the STM's ADC is sufficient, (once all oscillations are damped by modifying the circuit)
* Power whole OpAmp circuit with 3.3 volts in order to eliminate the need for the clamping diode at the ADC pin. This diode showed a high reverse current over temperature, which affected the measurement.
2020-02-05 18:30:34 +01:00
dda1209659
Remove INA126 because it doesn't work in this configuration. Replace by old subtractor circuit
2020-01-11 20:22:02 +01:00
cff848f02f
Small fixes and improvements
...
* Card detect pin used
* Fix SD card slot
* Improve routing and via placement
2020-01-03 18:34:21 +01:00
2c4c15e72b
Replace custom opamp circuit with INA126 instrumentation amp
2020-01-02 00:08:09 +01:00
a307557a41
Improved layout, Add QR code, Add external ADC option for 22 bit ADC
2019-12-26 18:01:55 +01:00
fe646769e7
Schematic beautify and layout improvments, Length matching for SDIO
2019-12-25 19:15:32 +01:00
a698e0b0e5
Add temperature sensor to PCB for compensation calculation.
2019-12-25 00:20:13 +01:00
c211cf659b
Newest changes in schematic and a preliminary complete layout
2019-12-23 22:25:38 +01:00
585ef85fab
PCB rework started
2019-10-02 14:12:33 +02:00
93ec69fa19
Fisrt draft. Will be reworked
2019-09-22 18:42:43 +02:00
