UKHASnet Wiki



===== Gateway =====

**Power Source:** 3.3V (from a DC/DC converter)

**Antenna:** SMA 1/2 wave rubber antenna 

**Code:** [[https://github.com/UKHASnet/UKHASnet_Firmware/tree/master/arduino_gateway|https://github.com/UKHASnet/UKHASnet_Firmware/tree/master/arduino_gateway]]

====== BOM ======
1x Stripboard, cut to size so all parts fit with 1 hole to spare before edge

1x 28DIP ATMega328P
  * [[http://uk.farnell.com/atmel/atmega328p-pu/mcu-8bit-atmega-20mhz-dip-28/dp/1715487|Farnell 1715487]] - £2.37 each

1x RFM69[H]W
  * [[http://ava.upuaut.net/store/index.php?route=product/product&path=71_63&product_id=109|HAB Supplies (max 20mW)]] - £3.59 each
  * [[http://www.hoperf.nl/RFM69HW|HopeRF (100mW)]] - € 3,22 each

1x TO-92 MCP1700 3.3V LDO
  * [[http://uk.farnell.com/microchip/mcp1700-3302e-to/ic-v-reg-ldo-250ma-to-92-3/dp/1296588|Farnell 1296588]] - £0.26 each

1x SMA 1/2 wave rubber antenna[[http://www.hoperf.nl/SDK4-868-SMA|Ideetron SDK4-868-SMA]] - €7.40 each

1x 28-pin DIP Socket

1x SMA board connector (HAB supplies has them)

===== Build Guide =====

==== Step 1 ====
  * Solder 28pin DIL IC socket to the strip board
  * Cut traces along the centre of the socket
  * Check that there is no conductivity between the two halves

==== Step 2 ====
  * Connect voltage output to Vcc as well as ground
  * Solder header for Serial (Tx and Rx) (optional)

==== Step 3 ====
  * Program the ATmega328 with the arduino bootloader
  * Upload simple script to the micro
  * Test that everything is working

==== Step 4 ====
  * Solder connecting wires to RFM69HW (GND, NSS, SCK, MISO, MOSI)
  * Line up with the ATmega328's corresponding pins. You'll need to bend your connecting wires a bit to fit through the holes in the strip board. Solder these in place.
  * The other 2 pins that need to be connected are VCC and DIO0 which are best connected with insulated wire.
    * VCC -> 3.3v
    * DIO0 -> pin 2 (Interrupt 0)

==== Step 5 ====
  * Upload gateway script to test RFM69HW
  * Check either with Funcube or that it is repeating to other nodes
    * Its been found that some modules are slightly off frequency and so need adjustment to match. The easist way is to use a funcube or RTL dongle and then adjust the frequency to line up with other nodes.
==== Step 6 ====
  * Solder SMA connector to ANT and GND pins

===== Schematic =====
{{:guides:arduinodesign.png|}}
===== Uploading new arduino scripts =====
  * As the current arduino is programmed just to use its internal oscillator it has a special board identification which needs to be added to your IDE. You need to find the boards.txt and add to the end
<code>
##############################################################

atmega328bb.name=ATmega328 on a breadboard (8 MHz internal clock)

atmega328bb.upload.protocol=stk500
atmega328bb.upload.maximum_size=30720
atmega328bb.upload.speed=57600

atmega328bb.bootloader.low_fuses=0xE2
atmega328bb.bootloader.high_fuses=0xDA
atmega328bb.bootloader.extended_fuses=0x07
atmega328bb.bootloader.path=arduino:atmega
atmega328bb.bootloader.file=ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb.bootloader.unlock_bits=0x3F
atmega328bb.bootloader.lock_bits=0x0F

atmega328bb.build.mcu=atmega328p
atmega328bb.build.f_cpu=8000000L
atmega328bb.build.core=arduino:arduino
atmega328bb.build.variant=arduino:standard
</code>
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