DSpeed

Speeduino ATMega2560 incarnation optimised for automated SMD assembly of most of the components. The MCU connections are based on Speedu v0.4.4d but there are differences in analogue and digital design and some extra features were added.

Main connectors

Caution

There should be an adequate fuse used on the main 12V power line for DSpeed. By default it should not exceed 2A and in case ETC module is used shouldn't be larger than 5A.

Left connector (B)

Pin	Signal	Function
B8C	PGND	Power ground
B7C	COIL4	Ignition coil 4 output
B6C	COIL3	Ignition coil 3 output
B5C	COIL2	Ignition coil 2 output
B4C	COIL1	Ignition coil 1 output
B3C	+5V	5V power output for sensors
B2C	MAP	External MAP sensor input
B1C	IAT	Inteke air temperature sensor input
B8B	PGND	Power ground
B7B	+9V	9V power output for 2-wire ABS sensor
B6B	-	Reserved
B5B	-	Reserved
B4B	-	Reserved
B3B	AGND	Analogue ground for sensors
B2B	CLT	Coolant temperature sensor input
B1B	TPS	Throttle position sensor input
B8A	12V	12V power input
B7A	Clutch	Clutch sensor input
B6A	LC5	Universal low current output
B5A	PUMP	Fuel pump relay control output
B4A	FAN	Fan relay control output
B3A	TACHO	Tachometer signal output
B2A	O2	External oxygen sensor input
B1A	A15	Universal analogue input

Right connector (A)

Pin	Signal	Function
A8C	INJ2	Injector 2 output
A7C	INJ1	Injector 1 output
A6C	IDLE	Idle PWM signal output
A5C	HC1	Universal high current output 1
A4C	FLEX	Flex fuel sensor input
A3C	WB_HT	Wideband oxugen sensor heater control output
A2C	WB_IA	Wideband oxugen sensor IA signal
A1C	CAM-	Camshaft position sensor negative input
A8B	INJ4	Injector 4 output
A7B	INJ3	Injector 3 output
A6B	HC2	Universal high current output 2
A5B	BOOST	Boost controler PWM signal output
A4B	SPDO	Speedometer signal output
A3B	WB_NE	Wideband oxugen sensor Nermest signal
A2B	WB_IP	Wideband Oxugen sensor IP signal
A1B	CAM+	Camshaft position sensor positive input
A8A	ST_A1	Stepper motor output A1
A7A	ST_B1	Stepper motor output B1
A6A	ST_B2	Stepper motor output B2
A5A	ST_A2	Stepper motor output A2
A4A	VSS	Vehicle speed sensor input
A3A	WB_VG	Wideband oxugen sensor virtual ground
A2A	CRANK-	Crankshaft position sensor negative input
A1A	CRANK+	Crankshaft position sensor positive input

Configuration jumpers & potentiometers

ID	Function	Description
J1	Ignition	Jumping 1-2 sets the cooil drivers voltage to 5V. Jumping 2-3 sets the cooil drivers voltage to 12V. For use with built-in ignition transistors (passive coils set witj J11-14) use of 12V may result in less heat dissipated in transistors although it may be case dependant and both settings will work. For active coils (set with J11-14) user has to know which input voltage is correct for them.
J2	O2	Jumping 1-2 feeds the Speeduino with the external O2 Sensor input signal. Jumping 2-3 feeds the Speeduino with the signal from the built-in wide band oxygen sensor controler.
J3	Crank	Must be ON together with J6 when internal conditioner for Crank position sensor is used. Must be OFF together with J6 when external conditioner is used.
J4	Cam	Must be ON together with J5 when internal conditioner for Cam position sensor is used. Must be OFF together with J5 when external conditioner is used.
J5	Cam	Must be ON together with J4 when internal conditioner for Cam position sensor is used. Must be OFF together with J4 when external conditioner is used.
J6	Crank	Must be ON together with J3 when internal conditioner for Crank position sensor is used. Must be OFF together with J3 when external conditioner is used.
J7	MAP	Jumping 1-2 connects the built-in MAP sensor to Speeduino A5 input while external source remains connected to A3 input. This allows for using one for atmospheric compensation (I think? Taken from Speeduino v0.4.4d). Jumping 2-3 sets the use of built-in MAP sensor only by conecting it to Speeduino A3 input. External sensor signal input should remain unconnected in this case!
J8	Crank	When ON a 10k pull-up resistor to 5V is added on Crank position sensor input.
J9	Cam	When ON a 10k pull-up resistor to 5V is added on Cam position sensor input.
J10	VSS	Jumping 2-3 adds a 10k pull-up resistor to 5V on Vehicle Speed Sensor input. USed for sensors with an open collector output pulling signal to ground only such us some Hall sensors. Jumping 1-2 adds a 270R pull-down on Vehicle Speed Sensor input. Used for 2-wire Hall sensors where signal is mixed with power as found in some ABS systems. For VR sensors leave jumper open.
J11	Ignition	For COIL1 output. Jumping 1-2 sets the "passive coil" option meaning the output is controled with a built-in transistor. Jumping 2-3 sets the "active coil" option meaning a 5/12V (see J1 setting) logic signal at the output.
J12	Ignition	For COIL2 output. Jumping 1-2 sets the "passive coil" option meaning the output is controled with a built-in transistor. Jumping 2-3 sets the "active coil" option meaning a 5/12V (see J1 setting) logic signal at the output.
J13	Ignition	For COIL3 output. Jumping 1-2 sets the "passive coil" option meaning the output is controled with a built-in transistor. Jumping 2-3 sets the "active coil" option meaning a 5/12V (see J1 setting) logic signal at the output.
J14	Ignition	For COIL4 output. Jumping 1-2 sets the "passive coil" option meaning the output is controled with a built-in transistor. Jumping 2-3 sets the "active coil" option meaning a 5/12V (see J1 setting) logic signal at the output.
J15	Crank	When ON the Crank- input is internally shortenned to ground. Should be ON when using VR sensor with internal conditioner and it is not grounded elswhere.
J16	Cam	When ON the Cam- input is internally shortenned to ground. Should be ON when using VR sensor with internal conditioner and it is not grounded elswhere.
J17	Idle	Jumping 1-2 choses normal signal for stepper motor driver. Jumping 2-3 will change STEP signal to IDLE signal from the MCU. This option is to be used with a DStage ETC module (DBW).
PR1	Crank	Potentiometr for setting the threshold voltage for Crank position sensor using built-in conditioner. For VR sensor typically set to 0V (measured at test point TP1), for Hall sensor typically set to 2.5V.
PR2	Cam	Potentiometr for setting the threshold voltage for Cam position sensor using built-in conditioner. For VR sensor typically set to 0V (measured at test point TP2), for Hall sensor typically set to 2.5V.
PR3	VVS	Potentiometr for setting the threshold voltage for vehicle speed sensor. For VR sensor typically set to 0V (measured at test point TP3), for Hall sensor typically set to 2.5V.

Internal connectors / modules

ID	Function	Description
P1	Crank/Cam	External VR conditioner socket (together with P2).
P2	Crank/Cam	External VR conditioner socket (together with P1).
P4	WB	Programming connector for wideband oxygen sensor controler.
M1	MCU	Main MCU module - Arduino ATMega2560 Pro.
M2	Speedo	Module for speedometer control - Arduino Xiao.
M3	Step	Stepper motor driver module for idle control - DRV8825 or equivalent.
BT	BT	Bluetooth communication module - HC-06.

ETC module (DBW)

Edit: this was not tested, recent trials with other flavour of my ETC show that the used bridge is most likely not great to put it midly. I'd rather recomend using a standalone ETC v1.3 or v2.2.

Since it's unlikely that the vehicle will need Eleectronic Throttle (DBW) and idle stepper motor driver at the same time there is an option in DSeed PCB to use the stepper driver slot for special deditacet variant of DStage ETC. You will find the production files and other documents on ETC repo.

This is the mapping of main connector pins normally used for stepper motor driver for the ETC purposes:

Pin	Sig step	Sig ETC	Function
A8A	ST_A1	MOT1	Throttle motor connection 1
A7A	ST_B1	MOT2	Throttle motor connection 2
A6A	ST_B2	TPS	Throttle position signal
A5A	ST_A2	ACC	Gas pedal position signal

• For the normal DSpeed TPS signal you can use either second position output from the throttle or from the gas pedal. Alternatively the same position signal as for ETC can be used although the input filter on DSpeed TPS input can interfear with ETC functionalituy so caution is recomended.
• For powering the ETC sensors use the +5V and GND pins.
• By default set J17 to "ETC" position (jumping 2-3).
• The ETC motor should not draw more than 3A, otherwise there may be a problem with the socket. It is a good idea to solder the ETC module directly to DSpeed PCB using long goldpins.
• There is no separate power input for ETC module therefore the fuse used for entire DSpeed has to be adequate for the module use (max ETC current draw, usually not exceeding 2A for midsized throttles) + ~1A for DSpeed power, not larger than 5A.
• There may be a problem with the USB cable hitting the ETC module. There are a few workarounds:
  • use bluetooth for communication,
  • solder ETC module directly to DSpeed PCB lower than the MCU module,
  • use USB-UART converter connected via RX and TX pins dedicated for bluetooth module,
  • solder USB cable directly to MCU module.

Speedometer module

Speedometer module is esentially Arduino Xiao. All other required HW is already present on DSpeed board.

Note

SW for the speedometer module is not ready at the moment. It will be added once I have some time. If you need it please contact me at dstagegarage@gmail.com

Tip

There is a standalone speedometer controller in my portfolio, please check ABS2SPEED project

Contact and other info

• email: dstagegarage@gmail.com
• YouTube: https://www.youtube.com/DStageGarage
• Speeduino forum: https://speeduino.com/forum/index.php