Shared Projects

3`15mhz transmitter board using an Attiny85 and TRX-315-LT-ND

You may be wondering why I made this when there are Arduino Nano or Arduino Mini Pro. It’s because I originally designed this to use ATMega328pB which came out a few years ago. Mini Pro and Nano do not have A6 or A7 in convenient place for breadboarding and on non ‘B’ version, they are only usable as analog input. The ‘B’ version also adds 2 GPIO pins that are not found on any Arduino board (official, clones, or offshoot variants) and to me this was a good reason to use ‘B’ version: 2 fully functioning analog pin that can use digitalRead or Write as well plus 2 digital pins. However Atmel and Microchip have not released this chip in DIP form for breadboarding, only in SMD packages so I needed to make a PCB to support this, have built in decoupling capacitors, built in ISP headers, built in power and D13 LED, built in crystal oscillator, and built in I2C resistor pads.

This board uses 0603 SMD resistors, capacitors, and LEDs. Please check my other uploaded design for slightly larger 0805 parts if you prefer those instead.

• D20 and D21 is available only when using internal oscillator
• D22 is Reset pin, generally I don’t change fuse to enable D22 because it’s a pain to reprogram this without reset!
• D23 and D24 is available only on ‘PB’ variant. Otherwise they are GND and VCC respectively
• D25 and D26 shares A6 and A7 on ‘PB’ variants only; on non-‘PB’ variants, those are strictly analog input only

BOM:

the PCB

IC1: ATMegaxx8 TQFP-32, I suggest ‘328 for maximum flash memory, SRAM, and EEPROM

J1-J4: zero-ohm 0603 jumper resistor, see Note 1 and 2 below

C1, C2, C3: 0.1uF ceramic 0603 cap, see Note 1 below

C4, C5: ceramic 0603 cap, matching oscillator’s spec, see Note 2 below

Q1: crystal of desired speed, see Note 2 below

R1: 10k ohm 0603 resistor

R2, R3: 470 ohm 0603 resistor (may want to adjust this depending on LED spec and color, I went with 1k for red because it’s too darn bright!)

R4, R5: 4.7K 0603 resistor, see Note 3 below

1 0603 LED of your favorite color for power (ie green)

1 0603 LED of another color for D13 (ie amber/yellow)

2 16 pins header 0.1" spacing (2.54mm)

1 push button switch Panasonic EVQP2 series or similar switch with 4 leads SPST, 4.7mm x 3.5mm

• Note 1: If you are not using PB variant of ATMega xx8 MPU, solder C2 capacitor plus J1 and J2 jumper. Otherwise do not populate these 3 parts to gain GPIO pin D23 and D24. This 2 pins are VCC and GND on non PB variants and can’t be used as GPIO.

• Note 2: If you are using internal oscillator, solder jumper J3 and J4 to connect pins to header and gain GPIO pin D20 and D21. If you are using external oscillator, do not populate J3 and J4. Instead add Q1 such as Abracon ABM3 series SMD crystal. ABM3 requires either 18pF or 20pF capacitors, check first before buying. Populate C4 and C5 with correct 0805 cap. The crystal pad is tailored for ABM3 and may not quite fit other similar sized SMD crystal.

• Note 3: pullup resistor for I2C (SCL and SDA) if needed. https://web.archive.org/web/20170115175107/http://www.nxp.com/documents/user_manual/UM10204.pdf to compute optimal resistor values but 4.7k are commonly used with 5v system.

You may be wondering why I made this when there are Arduino Nano or Arduino Mini Pro. It’s because I originally designed this to use ATMega328pB which came out a few years ago. Mini Pro and Nano do not have A6 or A7 in convenient place for breadboarding and on non ‘B’ version, they are only usable as analog input. The ‘B’ version also adds 2 GPIO pins that are not found on any Arduino board (official, clones, or offshoot variants) and to me this was a good reason to use ‘B’ version: 2 fully functioning analog pin that can use digitalRead or Write as well plus 2 digital pins. However Atmel and Microchip have not released this chip in DIP form for breadboarding, only in SMD packages so I needed to make a PCB to support this, have built in decoupling capacitors, built in ISP headers, built in power and D13 LED, built in crystal oscillator, and built in I2C resistor pads.

This board uses 0805 SMD resistors, capacitors, and LEDs. Please check my other uploaded design for slightly smaller 0603 parts if you prefer those instead.

• D20 and D21 is available only when using internal oscillator
• D22 is Reset pin, generally I don’t change fuse to enable D22 because it’s a pain to reprogram this without reset!
• D23 and D24 is available only on ‘PB’ variant. Otherwise they are GND and VCC respectively
• D25 and D26 shares A6 and A7 on ‘PB’ variants only; on non-‘PB’ variants, those are strictly analog input only

BOM:

the PCB

IC1: ATMegaxx8 TQFP-32, I suggest ‘328 for maximum flash memory, SRAM, and EEPROM

J1-J4: zero-ohm 0805 jumper resistor, see Note 1 and 2 below

C1, C2, C3: 0.1uF ceramic 0805 cap, see Note 1 below

C4, C5: ceramic 0805 cap, matching oscillator’s spec, see Note 2 below

Q1: crystal of desired speed, see Note 2 below

R1: 10k ohm 0805 resistor

R2, R3: 470 ohm 0805 resistor (may want to adjust this depending on LED spec and color, I went with 1k for red because it’s too darn bright!)

R4, R5: 4.7K 0805 resistor, see Note 3 below

1 0805 LED of your favorite color for power (ie green)

1 0805 LED of another color for D13 (ie amber/yellow)

2 16 pins header 0.1" spacing (2.54mm)

1 push button switch Panasonic EVQP2 series or similar switch with 4 leads SPST, 4.7mm x 3.5mm

Most 0805 SMD parts could theoretically have 0603 (resistors, capacitors, and LEDs) instead but you will have only about 0.3 mm on each side to solder on the pad.

• Note 1: If you are not using PB variant of ATMega xx8 MPU, solder C2 capacitor plus J1 and J2 jumper. Otherwise do not populate these 3 parts to gain GPIO pin D23 and D24. This 2 pins are VCC and GND on non PB variants and can’t be used as GPIO.

• Note 2: If you are using internal oscillator, solder jumper J3 and J4 to connect pins to header and gain GPIO pin D20 and D21. If you are using external oscillator, do not populate J3 and J4. Instead add Q1 such as Abracon ABM3 series SMD crystal. ABM3 requires either 18pF or 20pF capacitors, check first before buying. Populate C4 and C5 with correct 0805 cap. The crystal pad is tailored for ABM3 and may not quite fit other similar sized SMD crystal.

• Note 3: pullup resistor for I2C (SCL and SDA) if needed. https://web.archive.org/web/20170115175107/http://www.nxp.com/documents/user_manual/UM10204.pdf to compute optimal resistor values but 4.7k are commonly used with 5v system.

Uploaded from https://github.com/EnviroDIY/SensorModbusMaster/blob/master/hardware/Modbus-Mayfly_WingShield/RS485_Mayfly_Gerbers.zip with some file renames to fit oshpark

https://kicksat.github.io/

Snes Adapter M27C322 2 CI 74LS257

SNES Adapter M27C322

4-layer transceiver board for medical applications UCD Dart/CM 2018-07

Demonstration of MAX32660 as a motion co-processor. https://hackaday.io/project/160283-max32660-motion-co-processor

The Open Panzer Sound Card brings inexpensive, high quality, and open source sound functionality to RC models. It supports up to 32 GB of CD quality WAV files and provides 3 light outputs and a recoil servo output.

The physical board is actually made up of two components. First, an off-the-shelf PJRC Teensy 3.2 is used as the onboard processor. The Teensy is then plugged into a socket on our custom carrier board that adds a Micro SD card slot (max 32 GB), a Maxim 9768 10 watt mono amplifier, and headers for external connections.

There are two control methods available:

• By up to 5 channels of standard RC input. Each channel can be configured for multiple types of control, including switches of up to 6 positions. In this mode board settings are defined by an “ini” file which the user must include on the micro-SD memory card along with their sound files. A convenient INI Creator Utility can be downloaded which makes generating the ini file a breeze (Windows only). Instructions for using the sound card in RC mode can be found here
• Alternatively the sound card can be controlled via TTL serial by the Open Panzer TCB (Tank Control Board) or by any other microcontroller. When controlled by the TCB all configuration is handled by the TCB and its own Windows program called OP Config. Instructions for using the sound card with the TCB can be found here

Resources

• GitHub Page
• A discussion thread on the development of this card can be found on the Open Panzer Forum.
• Eagle Board and Schematic (zip)
• Printable Schematic (pdf)
• Bill of Materials - PDF - Excel

Changes in Version 3 include light and servo outputs, and mounting holes with identical spacing to the TCB.

Changes in Version 2 include a 10 watt amp (up from 2.6 watt in V1) and a reverse polarity diode on the voltage input.

Version 3, updated 7/23/2018

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amiketo_3d/201807

buffered DC level from 10 turn pot

for connecting a DIP ZIF socket to an icestick