https://www.pjrc.com/breakout-board-for-teensy-4-0

https://www.pjrc.com/breakout-board-for-teensy-4-0

Long Distance Serial Under Harsh Conditions

When you need to send a digital signal over a long distance in a noisy environment, this little DMX Signal Transmitter board is meant to be a “quick fix”. Terminal block connections allow it to be quick added to an existing project, when sending an ordinary signal just won’t work. On the other end, the DMX Signal Receiver Board is meant to receive the signal and turn it back into normal 5V signal.

Almost any type of serial signal may be used. WS2812B / NeoPixel data was the initial motivation for this board. Here are the first 2 boards being tested.

The transmitter is compatible with 3.3V signals, so this pair of boards also functions as a 3.3V to 5V level shifter.

Parts Placement Diagram

Bill Of Materials

All of the parts are available at Digikey.

1  MAX485                           MAX485EPA+-ND
1  DIP8 Socket                      AE9988-ND 
1  Terminal Block, 5.08mm, 5 pin    ED2583-ND, 609-3939-ND
1  Resistor, 150, 0805              311-150CRCT-ND, YAG3694CT-ND, P150CCT-ND
1  Resistor, 47K, 0805              311-47.0KCRCT-ND, YAG3363CT-ND, P47.0KCCT-ND
1  Resistor, 100K, 0805             311-100KCRCT-ND, YAG3359CT-ND, P100KCCT-ND
2  Capacitor, 22nF, 0805            490-1644-1-ND, 399-14577-1-ND, 445-6949-1-ND
1  Capacitor, 4.7uF, 0805           490-5422-1-ND, 1276-1065-1-ND, 490-3335-1-ND

How to use Digikey’s website to find alternate parts when any of these aren’t in stock.

Very inexpensive terminal blocks can also be found at Aliexpress or Ebay vendors, if you have time to wait for postal mail from China.

For DMX protocol and Serial data at 250 kbps/sec or slower, the MAX487 chip can be used. It has slew rate limiting, which improves the signal when used over low quality cables. But for WS2812 LEDs and fast serial (over 250,000 baud) the MAX485 or similar chips must be used.

First Actual Use

This is the Three Wishes Art Installation, featuring flame effects and WS2812 LEDs. More details can be found on this flame sensor page.

In this first photos, we tested in Martin’s driveway. The WS2812 data signals were generated by a Teensy 3.2 and OctoWS2811 board in the first of three units. Signals were sent down 25 foot cables to the other two. Amazingly, this worked great when testing in the driveway.

When the project was installed on the Playa at Burning Man, many challenges came up. The LEDs in the other two units went crazy. It turned out we had never tested in the driveway with the battery charger connected. When they removed the charger, the LEDs worked great, but running only from batteries and regularly connecting and removing the charger added yet another task to any already quite challenging project.

After the burn, we added two of these transmitter near the OctoWS2811 board, and receivers inside the other 2 units. Now all the LEDs work great, even while the charger is connected and recharging the batteries.

Receiving Serial Under Harsh Conditions

When you need to send a digital signal over a long distance in a noisy environment, this little DMX Signal Receiver board is meant to be a “quick fix”. At the other end, the DMX Signal Transmitter Board is meant to send the signal.

Almost any type of serial signal may be used. WS2812B / NeoPixel data was the initial motivation for this board. Here are the first 2 boards being tested.

Parts Placement Diagram

Bill Of Materials

All of the parts are available at Digikey.

1  MAX485                           MAX485EPA+-ND
1  DIP8 Socket                      AE9988-ND 
1  Terminal Block, 5.08mm, 5 pin    ED2583-ND, 609-3939-ND
1  Resistor, 150, 0805              311-150CRCT-ND, YAG3694CT-ND, P150CCT-ND
1  Resistor, 47K, 0805              311-47.0KCRCT-ND, YAG3363CT-ND, P47.0KCCT-ND
2  Resistor, 100K, 0805             311-100KCRCT-ND, YAG3359CT-ND, P100KCCT-ND
2  Capacitor, 22nF, 0805            490-1644-1-ND, 399-14577-1-ND, 445-6949-1-ND
1  Capacitor, 4.7uF, 0805           490-5422-1-ND, 1276-1065-1-ND, 490-3335-1-ND

How to use Digikey’s website to find alternate parts when any of these aren’t in stock.

Very inexpensive terminal blocks can also be found at Aliexpress or Ebay vendors, if you have time to wait for postal mail from China.

First Actual Use

This is the Three Wishes Art Installation, featuring flame effects and WS2812 LEDs. More details can be found on this flame sensor page.

In this first photos, we tested in Martin’s driveway. The WS2812 data signals were generated by a Teensy 3.2 and OctoWS2811 board in the first of three units. Signals were sent down 25 foot cables to the other two. Amazingly, this worked great when testing in the driveway.

When the project was installed on the Playa at Burning Man, many challenges came up. The LEDs in the other two units went crazy. It turned out we had never tested in the driveway with the battery charger connected. When they removed the charger, the LEDs worked great, but running only from batteries and regularly connecting and removing the charger added yet another task to any already quite challenging project.

After the burn, we added two of these transmitter near the OctoWS2811 board, and receivers inside the other 2 units. Now all the LEDs work great, even while the charger is connected and recharging the batteries.

Please read all the info carefully, especially the disclaimer, before using this board.

Full Details here: https://www.pjrc.com/pilot-light-flame-sensor-for-burning-man-art/

Parts Placement

Bill Of Materials

  1  Teensy LC
  3  LED, Green
  1  LED, Red
  1  Relay, RT424012, Mouser 655-RT424012
  1  Terminal Block Header, 4 pin, Phoenix 1755752, 277-1152-ND
  1  Terminal Block Header, 6 pin, Phoenix 1755778, 277-1154-ND
  1  Connector, 2 pin right angle header, Molex 22-05-3021
  1  LMC6482A Opamp, LMC6482AIMX
  1  74VHC123 Dual One-shot, 74VHC123AMXCT-ND
  1  LM2940IMPX-5.0 Voltage Regulator, LM2940IMPX-5.0/NOPBCT-ND
  1  Transformer, Audio 1K:8ohm, Mouser/Xicon TU003, Mouser 42TU003-RC
  2  IRFR5305 Mosfet, P-channel, IRFR5305PBFCT-ND
  2  PNP Transistor, 2N5087, TO-92, 2N5087-ND, 2N5087CS-ND
  2  Resistor, 10 ohm, 1%, 0805
  3  Resistor, 220 ohm, 1%, 0603
  2  Resistor, 470 ohm, 1%, 0603
  6  Resistor, 1K, 1%, 0603
  1  Resistor, 4.7K, 1%, 0805
  8  Resistor, 10K, 1%, 0603
  1  Resistor, 22K, 1%, 0603
  2  Resistor, 47K, 1%, 0603
  1  Resistor, 100K, 1%, 0603
  2  Resistor, 220K, 1%, 0805
  1  Resistor, 470K, 1%, 0805
  5  Resistor, 1M, 1%, 0805
  3  Capacitor, 4.7nF, C0G, 0805, 1276-6729-1-ND
  1  Capacitor, 1nF, 100V, Polyester Film, 493-3476-ND
  1  Capacitor, 10nF, 50V, Polyester Film, 493-3455-ND
  2  Capacitor, 0.1uF, 50V, X7R, 0603
  7  Capacitor, 1uF, 35V, X7R, 0805
  1  Capacitor, 100uF, radial, 6.3mm diameter, 493-13394-ND
  1  Capacitor, 100uF, 6.3V Tantalum
  1  Capacitor, 470uF, axial, 4053PHCT-ND or 4054PHBK-ND
  3  Diode, Dual Common Cathode, MMBD4148, MMBD4148CCCT-ND, MMBD4148CC-TPMSCT-ND
  1  Diode, Dual Schottky Common Cathode, BAT54C, BAT54C-FDICT-ND
  1  Diode, Schottky, 1A, 30V, B130, B130-FDICT-ND
  1  Diode, Zener, 12V, 1SMB5927, 1SMB5927BT3GOSCT-ND
  4  NPN Transistor, MMBT3904, MMBT3904FSCT-ND
  1  PNP Transistor, MMBT3906, MMBT3906FSCT-ND
  1  Pushbutton, 401-1426-1-ND (optional)
  2  header, 14 pins
  1  header, 4 pins (ok to cut from longer header)
  2  socket, 14 pins
  1  socket, 4 pins (ok to cut from longer socket, may need to shave side to fit)
  0  Connector, 3 pin right angle header, Molex 22-05-3031 --- not used
  0  MAX3483 RS485 Transceiver --- not used

How to use Digikey’s website to find alternate parts when any of these aren’t in stock.

Final Build With Enclosure

Detailed Info

https://www.pjrc.com/pilot-light-flame-sensor-for-burning-man-art/

Please read this article carefully to understand how this board works.

I/O Expander

The Monolith Synth Project needed to use a large number of these LED lit arcade buttons.

Dimming of the LEDs was required. Initially I considered using this Adafruit 16 Channel PWM board. But the LEDs in these buttons have integrated resistors which require 12 volts, so 16 transistor circuits and another board for reading the switches would have also been needed.

Instead I designed this board with everything required on a single small size board.

It uses the same PCA9685 chip for 12 bit PWM control on every LED, with mosfet drivers to handle 12V outputs, and also a MCP23017 chip to read the buttons. Every button has a discrete 1K pullup resistor (rather than using the higher impedance on-chip pullups) to help with use in the same cable bundles cross coupling to 12V PWM signals.

Parts Placement

Bill Of Materials

 1   MCP23017 16 bit GPIO                   MCP23017-E/SS-ND
 1   PCA9685 16 channel PWM                 568-11925-1-ND
 1   LP2950-5V LDO Voltage Regulator        296-20933-1-ND
 1   CAT811T Reset Chip                     CAT811TTBI-GT3OSTR-ND
16   FDV303N N-Ch Mosfet                    FDV303NCT-ND
 4   Header, 16x1                           609-3256-ND
 1   Header, 3x2                            67996-206HLF
 2   Connector, Molex 3 pin                 WM4201-ND
 1   Connector, Terminal Block 2 pin        277-1150-ND
 2   Capacitor, 0.1uF, 805                  478-1395-1-ND
 1   Capacitor, 4.7uF, 805                  490-6479-1-ND
 1   Capacitor, 100uF (10-47uF is ok)       399-6648-1-ND
16   Resistor, 1K, 603                      311-1.00KHRCT-ND
 3   Resistor, 10K, 603                     311-10.0KHRCT-ND

Mating Connectors

16   Housing, 4 position                    952-2229-ND
64   Crimp contact                          952-2158-ND
 1   Terminal Block, 2 position             277-1011-ND
 2   Housing, Molex 3 position              WM2001-ND
 6   Cript contact                          WM1114-ND

How to use Digikey’s website to find alternate parts when any of these aren’t in stock.

Monolith Synth

Four of these boards where used in the Monolith Synth project, shown at Tested and Bay Area Maker Faire 2017.