NPR modems FOR SALE: https://www.elekitsorparts.com/product/npr-70
Low prices (79$ fully assembled). International shipping.
Note for USA: Due to CFR 47 Part 97 FCC regulations, for the 70cm amateur radio band (restriction to 100kHz and 56kBaud), only the setting "modulation 20" of NPR-70 seems to be legal in USA. Please always check your local amateur-radio regulation before buying and using NPR70.
Modulation 20: Symbol Rate 50kS/s, bandwidth 100kHz, raw datarate 100kb/s raw, usable datarate 65kb/s.
If you want to discuss about NPR:
- via e-mail : f4hdk[at]free[dot]fr
- Public discussion English : the public chat room
- Public discussion French : Electrolab forum
- Mailing list (mainly USA) : groups.io
- Mailing list (mainly Europe) : groups.io
watch full screen.
Documentation
PCB Design (Gerbers, BOM, etc...)
PCB v02 | BOM Easy to provision Total cost ~80 euros per modem |
BOM (Bill Of Materials) |
PCB files | release note |
PCB v03 | Cheaper BOM Total cost ~65 euros per modem |
BOM (Bill Of Materials) |
PCB files | release note |
PCB v04 | Old version sold by Funtronics. Obsolete do not use. |
- |
PCB files | release note |
Add-on SRAM board | for PCB v04 only | - |
PCB files | release note |
PCB v05 | New version for Funtronics. Fits Funtronics enclosure |
BOM (Bill Of Materials) |
PCB files | release note |
Modem Firmware : binaries and sources
Stable version 2020_02_23 |
Beta version 2020_06_29 |
Binary file, band 70cm | Binary file, band 70cm |
Binary file, band 2m | Binary file, band 2m |
Release note | Release note |
Source code | Source code |
For automated (Master-) NPR modem control via eg. Raspberry Pi serial, you may need to delay the characters sent. Interactive control via screen or minicom works perfectly without special tools.
Please don't hesitate to use: https://npr.hb9gvd.ch/files/scd.c serial command delayer
To compile: gcc -Wall -o scd scd.c;chmod u1x scd
usage: scd [device] [bitrate] [delay in ms] ['command']
example: scd /dev/ttyACM0 921600 20 'radio on\r\n' # turns radio on
scd /dev/ttyACM0 921600 20 'status\r\n' # shows status page
scd /dev/ttyACM0 921600 20 '\03' # send CTRL-C to stop status page
scd displays received serial answers after timeout.
'\r\n' -> CR, Linefeed is required to finish command.
'\03' is the character to send for a CTRL-C
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