PeakTech 3442¶


Status	planned
Counts	50000
Connectivity	BLE
Measurements	voltage, current, resistance, capacitance, diode, continuity, frequency, duty cycle, period, temperature
Features	autorange, true-rms, hold, min/max, peak, lowpass, relative, current loop, bargraph, backlight
Website	peaktech.de

The PeakTech 3442 is a 50000 counts handheld digital multimeter with BLE connectivity. It is a rebranded CEM DT-987BT.

Hold the red MODE button to enable BLE communication.

Hardware¶

meter

HY3131 DMM chipset
TI 385B-1.2 reference
TI MSP430 MCU
TI CC2541 BLE communication

dongle

TI CC2540 BLE communication

Photos¶

Peaktech 3442 Bta 4 Pcb

Peaktech 3442 Pcb Overview

Peaktech 3442 Front

Peaktech 3442 Pcb Dmm Chip

Peaktech 3442 Pcb Mcu Ble

Peaktech 3442 Bta 4 Case

Protocol¶

The Peaktech meter ships with a USB dongle which is labelled "BTA-4", but turns out to be a TI "CC2540 USB Dongle V1.0" with a few parts not fitted (green LED, two push buttons, 2x5 programming header). The USB dongle registers with the PC as a USB ACM serial communication port. Its parameters are yet to get determined (uncertain which bitrate to use, and whether hardware handshake or modem control is involved, whether AT commands need to be sent, etc).

Without the USB dongle, the meter can be used with any other BLE central support in the PC. Communication is unidirektional (RX only on the PC side), data is received by means of BLE notifications.

The meter sends DMM packets of constant length (16(?) bytes each), with a fixed data pattern in some positions for synchronization (an assumption, yet to get verified). Thus this device lends itself to the serial-dmm driver's approach. The specific packet layout is yet to get determined (which fixed/reserved parts to check for reliable communication, which fields to get measurement values and their flags / modifiers from).

TODO

16 byte DMM packets, yet to get determined how to parse

Resources¶

TODO