Cerebro

../_images/cerebro.jpg

Specifications

Parameter Test Condition Value Unit
Weight   13.2 g
Dimensions Receiver 0.68 x 0.74 x 0.062 in
  Implant 1.05 x 0.40 x 0.75 in
Battery Life 520nm, 8mW 3s pulse, 6 pulses/min 4.25 (1700) hours (pulses)
Recharge time   1 hour
Light Wavelength HL63603TG (Red) 638 nm
  PLT5 520 (Green) 520 nm
Memory   8192 bytes
Trigger Latency   3.06 ± 0.05 ms
Rise Time   40 ± 10 ms
Fiber Diameter   200 μm
Light Output (per fiber) 520 nm diode coupled to 200 μm fiber 0 to 15 ± 0.5 mW
Input Voltage   2.7 to 4.2 V
Idle Current   11 mA
Peak Current Green Laser 370 mA

Bill of Materials

Tip

The pins on the vertical USB plug are very short and fail to protrude from standard thickness (~1.6mm) PCB. Therefore I recommend ordering thinner boards (~0.8mm) to make soldering the connector easier.

Caution

The Adafruit battery linked below has been confirmed to work with Cerebro. Other Li-poly batteries may be used to accommodate different weight or session length constraints, just make sure the battery capacity and C rating are capable of handling a peak current of 350 mA.

Qty Description Datasheet Vendor
1 Cerebro PCB   OSH Park
2 105 mAh Battery 1570 Adafruit
1 Microcontroller ATTINY84-20SSU Octopart
1 IR Sensor TSOP6138TR
1 DAC (12-Bit) LTC2630ACSC6-LZ12
1 EEPROM IC (64K) FT24C64A-ULR-T
1 Op Amp OPA237NA/3K
1 NPN Transistor FJX3904TF
1 Boost Converter MIC2288YD5 TR
1 Slide Switch AYZ0102AGRLC
1 Momentary Button B3U-1000P
1 Male micro USB vertical plug ZX20-B-5S-UNIT(30)
1 Male micro USB shielding ZX20-B-SLDC
1 Female micro USB horizontal socket 10118193-0001LF
1 Schottky Diode MBRM140T3G
1 10 μH Inductor LQH43CN100K03L
1 0603 Red LED LTST-C191KRKT
1 0603 Amber LED LNJ437W84RA
1 0603 0.1 μF Capacitor  
1 0603 10 μF Capacitor  
1 0603 2.2 μF Capacitor  
1 0603 6.8 Ω Resistor  
1 0603 27 Ω Resistor  
1 0603 100 Ω Resistor  
1 0603 2 kΩ Resistor  
2 0603 6.8 kΩ Resisor  
1 0603 12 kΩ Resistor  
3 0603 20 kΩ Resistor  

Build Instructions

Required Tools

  • Soldering iron
  • Tweezers
  • Flux pen
  • Solder wick
  • Wire cutters/strippers
  • Crazy glue
  • Hot glue gun

PCB Assembly

Uploading Firmware

Attention

If you have not yet setup the Arduino environment or the Cerebro Utility Shield, refer to Setting up Arduino IDE and/or Setting up Utility Shield before moving on.

  1. Turn on Cerebro and plug it into the Utility Shield as shown below.
../_images/cerebro_upload.png
  1. Open up the Arduino application and make the following selections under the Tools menu:
Board: “Cerebro (ATtiny84)”
Port: “COMXX (Arduino/Genuino Uno)”
Programmer: “Arduino as ISP”

../_images/tools_attiny84.png
  1. Burn the bootloader by selecting Tools -> Burn Bootloader
../_images/cerebro_bootloader.png
  1. Select the firmware that will be uploaded onto Cerebro File -> Sketchbook -> Cerebro Sketches -> cerebro
../_images/cerebro_firmware.png
  1. Upload the firmware by clicking the upload arrow
../_images/upload.png