BITboy

A handheld oscilloscope and behavioral setup debugger for neuroscientists. Your every-day companion for trouble shooting and setting up experimental instruments.

Read and write both analog and digital signals with ease. Check continuity in electronic circuits with the continuity checker. It can be used as a handheld oscilloscope or connected to your pc on a desk for higher resolution.

General disclaimer: Our BITboy is designed to work in a range of 0-5V and will take damage if connected to higher loads. Therefore, please be careful. We are planning a future version with overvoltage protection.

All provided files are in metric units (mm). The case can be 3D printed, while the cover can be lasercut or printed. The design aims at maximum reproduxibility with low total cost.

Commercial Parts List

Item	Quantity	Notes	Product Example Link
PCB	1 piece	custom design	eurocircuits.com
Arduino UNO R4 Wifi	1 piece	with LED matrix	arduino.cc
Pin Header 90 degrees	bar of 1x11 & 1x2	attached	conrad.de
Pin Header	bar of 1x6, 2x 1x8 & 1x10	attached	conrad.de
Battery Holder	1 piece	BC9VPC	digikey.de
Screw M2x8 mm	3 pieces	for battery holder	mercateo.com
Nut M2	3 pieces	for battery holder	digikey.de
Washer M2	3 pieces	for battery holder	digikey.de
9V Block Battery	1 piece		conrad.de
On-Off Switch	1 piece	L101011ML04Q	digikey.de
Rotary Encoder	1 piece	PEC11R-4215F-S0024-ND	digikey.de
DIP Switch	1 piece	DS01C-254-L-03BE	digikey.de
Piezo Buzzer	1 piece	490-4692-ND	digikey.de
Red LED	1 piece	set of 100	conrad.de
Tactile Switch	1 piece	450-1650-ND	digikey.de
BNC Connector	1 piece	ARF1690-ND	digikey.de
470R Resistor	1 piece	for LED	conrad.de
10K Resistor	1 piece	puldown for continuity check	digikey.de
Jumper Male-Female	2 wires	for continuity check	conrad.de

Case Parts

Item	Quantity	Notes	Product Example Link
Case	1 piece	custom design	3D printed
Acrylic Cover (3 mm)	1 piece	custom design	lasercut, can be printed
Screw M3x10 mm	8 pieces	self-tapping	mercateo.com
Washer M3	8 pieces		mercateo.com

All files are available as .STEP (for 3D CAD), .DXF Files (scaling: 1pt equals 1mm for laser cutting), .STL (3D Object for Printing). Electronics are provided as fusion arcive files (.f3z) and gerber files for PCB production with eurocircuits.

Wiring Diagram

PCB Layout

Pin Layout

Red LED

Arduino Pin	Connected to	Note
D12	red LED + (long)	via 470R resistor
GND	red LED -

Piezo Buzzer

Arduino Pin	Connected to	Note
D11	piezzo buzzer +	PWM (pulse width modulation)
GND	piezzo buzzer -

BNC 1 Analog I/O

Arduino Pin	Connected to	Note
A0	BNC connector signal pin	for DAC
GND	BNC connector shield/GND

BNC 2 Digital I/O

Arduino Pin	Connected to	Note
D5	BNC connector signal pin
GND	BNC connector shield/GND

DIP Switch (Dual in-line package)

Arduino Pin	Connected to	Note
D6	1 A
D7	2 A
D8	3 A
GND	1/2/3 B

Rotary Encoder with Button

Arduino Pin	Connected to	Note
D2	button 2	interrupt pin
GND	button 1
D3	encoder A	interrupt pin
D4	encoder B
GND	encoder shield & COM

Continuity Check

Arduino Pin	Connected to	Note
A3	1x2 pin header	with 10K pulldown resistor to GND
5V	1x2 pin header

Reset Button

Arduino Pin	Connected to	Note
RST	tactile switch A
GND	tactile switch B

Here you find an example for using the RST pin with a tactile switch

ON-OFF Switch and Battery

Arduino Pin	Connected to	Note
VIN	switch +
battery holder +	switch -
GND	battery holder -

Here you find more about powering options for Arduinos

Here you find an example and pictures for powering with a battery

Breakout Pins

Arduino Pin	Connected to	Note
AREF	1x11 pin header	for custom code
GND	1x11 pin header	for custom code
D10	1x11 pin header	for custom code
D9	1x11 pin header	for custom code
TX	1x11 pin header	for custom code
RX	1x11 pin header	for custom code
A2	1x11 pin header	for custom code
A1	1x11 pin header	for custom code
5V	1x11 pin header	for custom code
3.3V	1x11 pin header	for custom code
VIN	1x11 pin header	for custom code

BITboy Control Logic

Each reset/reboot of the device will start a readout procedure of the DIP switch to determine one of six operational settings modes.

The following table provides an overview about individual modules and their task during each mode:

Module	Analog In Pulse/Constant	Analog Out Pulse	Analog Out Constant	Digital In Pulse/Constant	Digital Out Pulse	Digital Out Constant
BNC_1 Analog I/O	Analog Read	Analog Write	Analog Write	Idle	Idle	Idle
BNC_2 Digital I/O	Idle	Idle	Idle	Digital Read	Digital Write	Digital Write
Rotary Encoder	Temporal Resolution	Set Voltage	Set Voltage	Temporal Resolution	Idle	Idle
Rotary Button	Idle	Hold	Toggle	Idle	Hold	Toggle
Output LED-Red	Idle	Write Indicator	Write Indicatr	Idle	Write Indicator	Write Indicator
Buzzer	Coupled Continuity
LED Matrix	Analog Voltage	Analog Voltage	Analog Voltage	Digital Voltage	Digital Voltage	Digital Voltage
Continuity Check	Active	Active	Active	Active	Active	Active
Breakout Pins	Idle	Idle	Idle	Idle	Idle	Idle

Lasercutting

We used a Trotec Speedy Flex lasercutter with a 100W CO2 laser with the following settings for 3 mm acrylic glass:

Parameter	Cutting Quality
Power	40 Watts
Speed	0,2 %
Laser Source	CO2
Frequency	20000
Passes	1
Power Correction	10
z-Offset	0

3D Printing

We suggest printing with PLA, tough PLA or ABS for best results. Any standard print settings will provide aceptable results. Avoid fancy materials to reduce cost and effort.

For the case, we used a Babulab A1 mini filament printer with generic PLA.