This project comes as a KIT. It includes these components:
- Low-cost DMM (digital multimeter) M830D
- TX (transmitter) circuitand wireless module TX-433. These are mounted within the DMM housing.
- RX (receiving) circuitwith a wireless module RX-433, LCD and piezo buzzer.
The general idea is to read all LCD data from a cheap DMM (directly from its main chip.) This data is sent and received by wireless modules, read by the RX circuit and then displayed again. Sounds pretty easy, not?
Here are the technical specifications:
- Low power operation (8-10 mA @9V) with PIC 18F452 (TX) and 18F2550 (RX) microcontrollers running at 4 MhZ.
- Sampling rate: around 3 samples/sec.
- Max. distance between the RX and TX circuits: 30m indoors and 100m outdoors.
- Software is 100% upgradable with a simple bootloader.
- Low power LED blinks when sending / receiving data.
- TX circuit: PCB Dimensions: 30 x 31 mm or 1″18 x 1″22, weight: 8 grams.
- RX circuit: LCD contrast adjustable by user.
- RX circuit: PCB Dimensions: 40 x 41 mm or 1″57 x 1″61, weight: 10 grams.
- This product is available as a KIT from our online shop.
- KIT step-by-step construction guide.
- Source code (CCS C) , pcb layouts and schematics (Eagle) can be purchased separately.
Hex files available. Last update: June 1, 2006.
RS232 interface: JP2 provides the interface to connect to your COM port and hyper terminal. Also used for bootloading (module software update.) Check under the download section below for the latest version. Bootloading of the HEX-file can be done with Tiny Bootloader.
RX circuit, LCD contrast Adjust: Connect pin 5, JP3 to +5V before powering up. Release when the desired the contrast is reached.
Downloads: right-click & save as
|TX circuit HEX: 025tx_v10.hex for 18f452 – May 31, 2006.
RX circuit HEX: 025rx_v009.hex for 18f2550 – June 1, 2006.
Both can be bootloaded with Tiny PIC bootloader through the RS232 port (JP2)
|TX & RX circuit schematics, pcb layouts and CCS C Source Code: not released, but you can buy a license on our Products page.|
For more detail: Wireless MultiMeter using PIC18F452 Microcontroller