rusefi-hardware/lambda-x2

About

For firmware see https://github.com/dron0gus/wideband (based on https://github.com/mck1117/wideband)

See rusEFI forum: F103 dual channel wideband controller + EGT + 2 x AUX In + 2 Aux out

• STM32F103 dual channel wideband AFR controller supporting Bosch LSU4.9 (LSU4.2 and LSU_ADV work in progress)
• CAN and analog output
• x2 EGT input using MAX31855KASA or MAX31856
• x2 auxilary analog input: 0..5V with pull-up or pull-down (configurable by soldering resistor). One can be used to source 5V to external sensor.
• x2 2 auxilary output 0..5V. Also can be used for slow PWM signal output.
• x2 open drain outputs: BTS3028 (5A)
• Bluetooth TunerStudio connectivity

See also https://github.com/rusefi/rusefi/wiki/WBO

Known issues

ESR measurement crosstalk between channels (rev0 and rev1)

HW has three different outputs for Nernst cell ESR measurement with different output resistance: 6.8K for LSU4.2, 22K for LSU4.9 and 47K for LSUADV. Idea was to allow the user to set the type of sensor from SW only.

Each ESR output is driven by one MCU GPIO. GPIOs for unused ESR measurement outputs are kept in Hi-Z (input) state and does not affect ESR measurement.

Same GPIO drivers ESR outputs for both channels. This is the root cause of problem

Problem: unused ESR output with GPIO in Hi-Z state connect Nernst cell outputs from left and right channel through two resistors. This causes crosstalk between channels and inaccurate ESR measurement. Wrong ESR measurement causes incorrect sensor temperature calculation. This can lead to inaccurate AFR measurement, overheating or underheating of the sensor.

Same issue for LSU4.9 bias resistors R22 and R70.

Solution:

Boards come with all ESR drive resistors populated. You have to remove unnecessary resistors.

If LSU4.2 sensor is used: remove R24, R25, R71, R72, R22, R70. Keep R41 and R73 - 6.8K

If LSU4.9 sensor is used: remove R25, R41, R72, R73. Keep R24 and R71 - 22K

If LSUADV sensor is used: remove R24, R41, R71, R73, R22, R70. Keep R25 and R72 - 47K

This will be (or not) solved in next revision of HW.

Pinout

Main connector pinout

Interactive Pinout

Uart pinout

J3 connector. Colors are default for cheap usb-to-uart converters based on CP2101. Connect red wire if you want to power device from USB.

Bluetooth

No extra steps needed to initialize JDY-33. Default baud rate is 115200.

TunerStudio configuration

Baudrate is 115200 .ini file

Firmware Upload

DODO

Changelog

rev 1

• Switch to 64 pin STM32/GD32
• Add 8MHz HSE oscillator (better clock stability for CAN over wide temperature range)
• Use DAC (instead of PWM) outputs for driving Ip
• Move BT to UART3/USART3, keep USART1 for bootloader/debug
• Drive BT's EN signal from MCU
• Fix RC filters on heater outputs for better voltage measurement
• Use separate ADC input for Vbat measurement
• Use ADC channels for AUX outputs monitoring/diagnostic
• Use PWM noise cancelation circuit on AUX analog outputs
• Removed useless/non-functional protection of Vm outputs
• Fix board outline to fit two types of enclosure ("plastic top" and "alloy brick")
• Add testpoints for TC2030 JTAG probe
• Add buttons for Reset and Boot0
• Add Cfg1 and jumpers
• Replace fuse holder with resettable 0.2A 33V fuse
• Two status LEDs for separate status indication for left and right channel
• Silkscreen labels around testpoints
• Silkscreen labels at uart connector on both sides of PCB
• Un_3x_sense formula is now 0.247 + 3.15 * (Un - Vm)
• Un_sense (not gained) is also routed to ADC input
• Protection from possible Ip current when MCU in reset/bootloader
• White "power on" LED replaced with green
• Main connector pinout added to top silkscreen
• AUX connector pinout added to top silkscreen

rev 0

Seems to work with proper C10/C35 using https://github.com/rusefi/wideband/releases/tag/20230210-does-not-match-binaris