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en:tech:ut71 [2022/11/27 12:06] – [UT71B Interface] bullar | en:tech:ut71 [2022/11/30 11:49] (current) – [Downloads] bullar | ||
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- | ===== UT71B Interface ===== | + | ====== UT71B Interface |
The digital multimeter series UT71 from [[http:// | The digital multimeter series UT71 from [[http:// | ||
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| 1 | Housing (3D print or laser cut) {{: | | 1 | Housing (3D print or laser cut) {{: | ||
- | ==== Schematic ==== | + | ===== Schematic |
{{: | {{: | ||
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The TxD diode is optional and not supported by the software (yet). | The TxD diode is optional and not supported by the software (yet). | ||
- | ==== Housing ==== | + | ===== Housing |
{{: | {{: | ||
I used a laser cut housing based on 2mm white acryl. The design was prepared with Inkscape. | I used a laser cut housing based on 2mm white acryl. The design was prepared with Inkscape. | ||
Depending on the thickness of your wiring you may not need all layers. In my example I only used 4 pieces. | Depending on the thickness of your wiring you may not need all layers. In my example I only used 4 pieces. | ||
- | {{: | ||
- | ==== Assembly ==== | + | |
+ | ===== Assembly | ||
Cut and engrave on your laser cutter of choice. Prepare the small piece of PCB (perfboard). Glue the IR transistor (dark blue)and the IR LED. The flat part should be on the left for each. Solder the parts and the SMD resistors as shown on the picture. Last but not least connect the four wire of the PL2303HX. | Cut and engrave on your laser cutter of choice. Prepare the small piece of PCB (perfboard). Glue the IR transistor (dark blue)and the IR LED. The flat part should be on the left for each. Solder the parts and the SMD resistors as shown on the picture. Last but not least connect the four wire of the PL2303HX. | ||
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{{: | {{: | ||
{{: | {{: | ||
- | ==== Software ==== | ||
- | {{ : | ||
- | The S/W is written with [[https:// | ||
- | As I have just now only a license for OS X I can't provide binaries for Windows and Linux. | ||
- | The S/W has mainly | + | ===== Protocol ===== |
+ | |||
+ | The logic analyser revealed the following signal frame: | ||
+ | |||
+ | {{ : | ||
+ | |||
+ | As we can see the multimeter sends 11 Bytes with 2400 Baud, 7 bits and ODD parity in ASCII format every approx. 650ms. With our built hardware we are now able to use a standard UART-program to analyse the protocol further. After some long iterations (and a lot of coffees) the eleven bytes have following meaning: | ||
+ | |||
+ | < | ||
+ | # Decode 11 bytes from UT71A/B/C | ||
+ | # ============================== | ||
+ | # Byte / Bit 6 5 4 3 2 1 0 | ||
+ | # [0] Digit 1 0 1 1 =====Digit====== | ||
+ | # [1] Digit 2 0 1 1 =====Digit====== | ||
+ | # [2] Digit 3 0 1 1 =====Digit====== | ||
+ | # [3] Digit 4 0 1 1 =====Digit====== | ||
+ | # [4] Digit 5 0 1 1 =====Digit====== | ||
+ | # [5] Range 0 1 1 0 =see below= | ||
+ | # [6] Unit | ||
+ | # [7] Coupling | ||
+ | # [8] Info | ||
+ | # [9] ' | ||
+ | # [10] ' | ||
+ | # | ||
+ | # Digit: 0x30..0x39 = ' | ||
+ | # REL not sent | ||
+ | # No tansmission in HOLD state | ||
+ | # If NEG set at Range 15 sent value is duty cycle | ||
+ | # No LowBat info sent | ||
+ | # Storaged data not accessable | ||
+ | </ | ||
+ | |||
+ | Depending on the chosen measuring range the '' | ||
+ | |||
+ | < | ||
+ | Unit: 0 | ||
+ | Range: | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | ' | ||
+ | </ | ||
+ | |||
+ | ===== Software ===== | ||
+ | |||
+ | <WRAP group> | ||
+ | <WRAP half column> | ||
+ | {{ : | ||
+ | </ | ||
+ | <WRAP half column> | ||
+ | {{: | ||
+ | </ | ||
+ | </ | ||
+ | |||
+ | Based on the protocol information I prepared a tiny Python program to receive | ||
- | ^ Version ^ Remark ^ OS ^ File ^ | + | ===== Downloads ===== |
- | | V0.10 | Initial Version | Mac OS X 10.9+ | {{: | + | |
- | ==== Donate ==== | + | * {{: |
+ | * {{ : | ||
+ | ===== Donate | ||
If you like my articles feel to donate a cappuccino or so... | If you like my articles feel to donate a cappuccino or so... |