4 layers190 × 110 mm
2 layers44.6 × 79.6 mm
Injector driver 2
dan-mills/microJectMQL lubrication system using automotive injectors to lubricate cutting tools.
- Size
- 44.6 × 79.6 mm
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 96
- Nets
- 69
- Pads
- 262
- Tracks, vias
- 573, 182
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 12 Oct 2026
- Updated
- 20 Oct 2026
Overview
Injector driver 2 is an open-source printed circuit board by dan-mills, from the dan-mills/microJect repository on GitHub, published under the Apache-2.0 licence. It is a 2-layer board of 44.6 × 79.6 mm with 96 parts on 69 nets, routed with 573 tracks and 182 vias.
It is built around the B2405S-1WR3, ISO3082DW and TPS62933DRL, with the ACPL-227-50BE, HT7533-1(SOT89) and AO3400A among its other parts. Its parts include 26 resistors, 22 capacitors, 14 diodes, 10 connectors and 6 ICs. It belongs with the STM32 boards of this library.
Main components
10
B2405S-1WR3
SIP,11.6x6mm-40℃~+105℃ 1 1.5kV 10.16mm 11.6mm 1W 200mA 21.6V~26.4V 2400uF 260kHz 30mVp-p 5V 6mm 88% 8mA Short Circuit Protection、Overheat Protection、Automatic fault recovery Unregulated type SIP,11.6x6mm Isolated Power Modules ROHSYLPTECIsolated Power Modules
ISO3082DW
SOIC-16-300mil-40℃~+85℃ 1 1 200Kbps 2500 256 3.15V~5.5V 4.5V~5.5V 50kV/us Failure protection circuit Half-Duplex ±4kV SOIC-16-300mil Isolated RS-485/422 Transceivers ROHSTexas InstrumentsIsolated RS-485/422 Transceivers
TPS62933DRL
SOT-583-40℃~+150℃@(TJ) 1 12uA 2.2MHz 3.8V~30V 3A 800mV~22V Adjustable Buck Buck Built-in Yes SOT-583 DC-DC Converters ROHSTexas InstrumentsDC-DC Converters
ACPL-227-50BE
SO-8-4.4mm-55℃~+110℃ 1.2V 2 200mW 2us 3.75kV 3us 400mV@8mA,2.4mA 50% 50mA 50mA 600% 6V 80V DC Phototransistor SO-8-4.4mm Transistor, Photovoltaic Output Optoisolators ROHSBroadcom LimitedTransistor, Photovoltaic Output Optoisolators
HT7533-1(SOT89)
SOT-89SOT-89 Voltage Regulators - Linear, Low Drop Out (LDO) Regulators ROHSAXTEKUncategorised
AO3400A
SOT-23-55℃~+150℃ 1 N-channel 1.45V 1.4W 30V 48mΩ@2.5V 5.7A 50pF 630pF 75pF 7nC@10V N-Channel SOT-23 MOSFETs ROHSAlpha & Omega SemiconductorMOSFETs
B140HW-7-HXY
SOD-123SOD-123 Schottky Diodes ROHSHXY MOSFETSchottky DiodesNUP2105L
SOT-23-55℃~+150℃ 100nA 2 24V 30pF 32V 350W@8/20us 44V 8A@8/20us Bidirectional IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 TVS SOT-23 ESD and Surge Protection (TVS/ESD) ROHSonsemiESD And Surge Protection (TVS/ESD)
IHLP2020BZER100M11
SMD,5.2x5.2mm10uH 169mΩ 2.2A 2A ±20% SMD,5.2x5.2mm Power Inductors ROHSVishay IntertechnologyPower Inductors
DHA-04TQ
SMD,P=1.27mm-40℃~+85℃ 1,000 cycles 1.27mm 24V 25mA 4 SPST SMD,P=1.27mm DIP Switches ROHSDiptronicsDIP Switches
README
README.mdmicroJect
MQL lubrication system using automotive injectors to lubricate cutting tools.
Control is via modbus RTU on RS485 or via switches and pots (Two channels only in that mode). Power input is 24V and power delivered to the injector heads is 12V at up to about 3A total from an on board power converter.
Firmware is written in Rust with Embassy as the framework and the processor on the board is an STM32F030k6.
#Electrical Interface
| Power supply | 24V @ 1.5A but usually much less. |
| Injector outputs | 12V @1A, 3A total max |
| Digital inputs | 2 Opto isolated, 24V max |
| Analogue inputs | 2, 3.3V max, intended for potentiometers |
| Serial interface | Isolated RS485 |
Operating modes
There is a 4 way dip switch on the board which configure the operating modes
| Switch | Function |
|---|---|
| 1 | Enables local control mode, the opto inputs and analog control the first two channels |
| 2 | Modbus alternate address, sets the modbus address to be 9 instead of 8 |
| 3, 4 | Modbus baud rate |
Baud rates
| SW 3 | SW 4 | Baud Rate |
|---|---|---|
| Off | Off | 4800 |
| Off | On | 9600 |
| On | Off | 19200 |
| On | On | 115200 |
Modbus support
Modbus interface is RTU over RS485 half duplex, formatted as 8-E-1.
Coils
| Coil | Description |
|---|---|
| 1 | Pulse enable for channel 1 |
| 2 | Pulse enable for channel 2 |
| 3 | Pulse enable for channel 3 |
| 4 | Pulse enable for channel 4 |
Note in modbus mode the coils will switch off 5 seconds after the last communication is received to avoid spilling coolant everywhere.
Holding Registers
| Register | Description |
|---|---|
| 1 | Channel 1 pulse length |
| 2 | Channel 1 period |
| 3 | Channel 2 pulse length |
| 4 | Channel 2 period |
| 5 | Channel 3 pulse length |
| 6 | Channel 3 period |
| 7 | Channel 4 pulse length |
| 8 | Channel 4 period |
Discrete inputs
| Input | Description |
|---|---|
| 1 | Enable input for ch1 when in local control mode |
| 2 | Enable input for ch2 when in local control mode |
Analogue inputs
| Input | Description |
|---|---|
| 1 | 0-3.3V period control input for channel 1 when in local control mode |
| 2 | 0-3.3V period control input for channel 2 when in local control mode |
Both the discrete inputs and the analogue channels can be read over modbus when not using local mode so you can readily use them for other things when using modbus for control.
When in local control mode (SW1 is on) the pulse length is defaulted to 1ms and the potentiometers control the pulse rate (1 - 1000Hz).
Parts
96| Qty | Value | Footprint | References |
|---|---|---|---|
| 15 | 10k | Resistor_SMD:R_0603_1608Metric | R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R15, R16, R19, R22, R28 |
| 11 | 1uF | Capacitor_SMD:C_0603_1608Metric | C1, C2, C3, C4, C5, C6, C7, C8, C19, C20, C21 |
| 8 | LED | LED_SMD:LED_0603_1608Metric | D4, D5, D6, D7, D8, D9, D10, D14 |
| 8 | TestPoint | TestPoint:TestPoint_THTPad_2.5x2.5mm_Drill1.2mm | TP1, TP2, TP3, TP4, TP5, TP6, TP7, TP8 |
| 7 | 1k | Resistor_SMD:R_0603_1608Metric | R20, R21, R23, R29, R30, R31, R32 |
| 5 | Conn_01x02_Pin | PHOENIX THD:PHOENIX_1751099 | J7, J8, J9, J10, J12 |
| 4 | 10uF | Capacitor_SMD:C_1206_3216Metric | C29, C30, C31, C32 |
| 4 | AO3400A | Package_TO_SOT_SMD:SOT-23 | Q3, Q4, Q5, Q6 |
| 4 | B140HW-7 | Diode_SMD:D_SOD-123 | D11, D12, D13, D15 |
| 4 | MountingHole | MountingHole:MountingHole_3.2mm_M3_ISO14580_Pad | H1, H2, H3, H4 |
| 3 | 100nF | Capacitor_SMD:C_0603_1608Metric | C27, C28, C34 |
| 2 | 22uF 35V | Capacitor_SMD:CP_Elec_5x5.7 | C23, C25 |
| 2 | 4k7 | Resistor_SMD:R_0603_1608Metric | R17, R18 |
| 2 | Conn_01x04_Socket | PHOENIX THD:PHOENIX_1751112 | J3, J4 |
| 2 | NUP2105L | Package_TO_SOT_SMD:SOT-23 | D3, D16 |
| 1 | 10uF 50V | Capacitor_SMD:C_1206_3216Metric | C33 |
| 1 | 120R | Resistor_SMD:R_1206_3216Metric | R1 |
| 1 | 140k | Resistor_SMD:R_0603_1608Metric | R27 |
| 1 | 470pF 1kV | Capacitor_SMD:C_1206_3216Metric | C9 |
| 1 | 6.8uH | Inductors SMD:IND_MURATA-PS_4500 | L3 |
| 1 | ACPL-227-50BE | ICs And Semiconductors SMD:SOIC127P700X220-8N | IC4 |
| 1 | B2405S-1WR3 | Converter_DCDC:Converter_DCDC_Murata_CRE1xxxxxx3C_THT | U2 |
| 1 | Conn_01x02 | Connector_PinHeader_2.54mm:PinHeader_1x02_P2.54mm_Vertical | J2 |
| 1 | Conn_01x03_Socket | PHOENIX THD:PHOENIX_1751109 | J1 |
| 1 | HT7533-1(SOT89) | ICs And Semiconductors SMD:SOT89 | IC3 |
| 1 | ISO3082DW | Package_SO:SOIC-16W_7.5x10.3mm_P1.27mm | U4 |
| 1 | Programming header | Connector_PinHeader_2.54mm:PinHeader_1x06_P2.54mm_Vertical | J5 |
| 1 | STM32F030K6Tx | Package_QFP:LQFP-32_7x7mm_P0.8mm | U1 |
| 1 | Switch | Switches:SW_DIPTRONICS_DHA-04TQ | SW1 |
| 1 | TPS62933 | Package_TO_SOT_SMD:SOT-583-8 | U7 |
Questions
How big is the Injector driver 2 PCB?
It measures 44.6 × 79.6 mm and has 2 copper layers, 1.6 mm thick.
What parts does the Injector driver 2 use?
96 parts, built around the B2405S-1WR3, ISO3082DW, TPS62933DRL and ACPL-227-50BE. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the Injector driver 2 KiCad files?
From the dan-mills/microJect repository on GitHub, at the commit this page was made from: the board is injector driver 2/injector driver 2.kicad_pcb and its schematic injector driver 2/injector driver 2.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Injector driver 2 design in my own project?
Its repository publishes it under the Apache-2.0 licence: you may reuse it on that licence's terms (keep the author's notice, and for a copyleft licence share your changes alike).
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