comparison: content/hp34970a_3.rst
content/hp34970a_3.rst
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| 7 :Tags: HP, 34970A, DMM, repair, test equipment | 7 :Tags: HP, 34970A, DMM, repair, test equipment |
| 8 :series: HP 34970A repair | 8 :series: HP 34970A repair |
| 9 :series_index: 3 | 9 :series_index: 3 |
| 10 | 10 |
| 11 | 11 |
| 12 As explained in `the previous post in this series <{static}/hp34970a_2.rst>`_, | 12 As explained in `the previous post in this series <{filename}/hp34970a_2.rst>`_, |
| 13 I've started to sniff the serial protocol between the main board and | 13 I've started to sniff the serial protocol between the main board and |
| 14 the display panel so I can replace the failed VFD by an OLED or TFT | 14 the display panel so I can replace the failed VFD by an OLED or TFT |
| 15 display managed by an arduino or similar. | 15 display managed by an arduino or similar. |
| 16 | 16 |
| 17 Protocol | 17 Protocol |
| 69 in 3 characters (the 3 digits). | 69 in 3 characters (the 3 digits). |
| 70 | 70 |
| 71 | 71 |
| 72 Indicator flags | 72 Indicator flags |
| 73 --------------- | 73 --------------- |
| 74 | 74 |
| 75 The indicator flags are always sent as 4 bytes, each bit controlling | 75 The indicator flags are always sent as 4 bytes, each bit controlling |
| 76 one indicator. | 76 one indicator. |
| 77 | 77 |
| 78 The indicator flags I've been able to identify so far | 78 The indicator flags I've been able to identify so far |
| 79 are below. | 79 are below. |
| 80 | 80 |
| 81 Let's say the frame is: ``<0x0A> <0x04> <F1> <F2> <F3> <F4>``, then: | 81 Let's say the frame is: ``<0x0A> <0x04> <F1> <F2> <F3> <F4>``, then: |
| 82 | 82 |
| 83 | 83 |
| 84 - F1.8 = | 84 - F1.8 = |
| 85 - F1.7 = HI | 85 - F1.7 = HI |
| 86 - F1.6 = Alarm | 86 - F1.6 = Alarm |
| 87 - F1.5 = LO | 87 - F1.5 = LO |
| 88 - F1.4 = Channels | 88 - F1.4 = Channels |
| 89 - F1.3 = Channels box | 89 - F1.3 = Channels box |
| 90 - F1.2 = Mx+B enabled | 90 - F1.2 = Mx+B enabled |
| 91 - F1.1 = Alarm enabled (or the alarm frame) | 91 - F1.1 = Alarm enabled (or the alarm frame) |
| 92 | 92 |
| 93 - F2.5 = 4W | 93 - F2.5 = 4W |
| 94 - F2.4 = Alarm 1 ? | 94 - F2.4 = Alarm 1 ? |
| 95 - F2.3 = Alarm 3 | 95 - F2.3 = Alarm 3 |
| 96 - F2.2 = Alarm 4 | 96 - F2.2 = Alarm 4 |
| 97 - F2.1 = Alarm 2 | 97 - F2.1 = Alarm 2 |
| 98 | 98 |
| 99 - F3.6 = | 99 - F3.6 = |
| 100 - F3.5 = | 100 - F3.5 = |
| 101 | 101 |
| 102 - F4.8 = | 102 - F4.8 = |
| 103 - F4.7 = CONFIG (not sure) | 103 - F4.7 = CONFIG (not sure) |
| 104 - F4.6 = | 104 - F4.6 = |
| 105 - F4.5 = MON | 105 - F4.5 = MON |
| 106 - F4.4 = VIEW | 106 - F4.4 = VIEW |
| 107 - F4.3 = | 107 - F4.3 = |
| 108 - F4.2 = | 108 - F4.2 = |
| 109 - F4.1 = | 109 - F4.1 = |
| 110 | 110 |
| 111 | 111 |
| 112 | 112 |
| 113 Quick prototype | 113 Quick prototype |
| 114 =============== | 114 =============== |
| 115 | 115 |
| 116 With this very incomplete reverse ingeeniring of the communication, I | 116 With this very incomplete reverse ingeeniring of the communication, I |
| 117 have enough meat to try a quick prototype. | 117 have enough meat to try a quick prototype. |
| 129 As you can see, it works: I have the main content od the VFD display | 129 As you can see, it works: I have the main content od the VFD display |
| 130 on my TFT module! | 130 on my TFT module! |
| 131 | 131 |
| 132 .. image:: {static}/images/hp34970a/poc_display_mux_off.jpg | 132 .. image:: {static}/images/hp34970a/poc_display_mux_off.jpg |
| 133 :alt: The FTF display showing the main area and the current channel area. | 133 :alt: The FTF display showing the main area and the current channel area. |
| 134 | 134 |
| 135 .. image:: {static}/images/hp34970a/poc_display_vdc.jpg | 135 .. image:: {static}/images/hp34970a/poc_display_vdc.jpg |
| 136 :alt: The same with the channel 209 configured as VDC, 6.5digits. | 136 :alt: The same with the channel 209 configured as VDC, 6.5digits. |
| 137 | 137 |
| 138 | 138 |
| 139 The job is far from finished however: I still have to figure out how | 139 The job is far from finished however: I still have to figure out how |
| 142 mega328. This seems to mbe necessary because I have glitches | 142 mega328. This seems to mbe necessary because I have glitches |
| 143 sometimes. But I'm very happy it worked almost at my first try. I was | 143 sometimes. But I'm very happy it worked almost at my first try. I was |
| 144 quite surprised since the baudrate is above the maximum officially | 144 quite surprised since the baudrate is above the maximum officially |
| 145 supported one (115200). | 145 supported one (115200). |
| 146 | 146 |
| 147 I'll release the code of the prototype any time soon. | 147 I'll release the code of the prototype any time soon. |
| 148 | 148 |
| 149 .. _SoftwareSerial: https://www.arduino.cc/en/Reference/SoftwareSerial | 149 .. _SoftwareSerial: https://www.arduino.cc/en/Reference/SoftwareSerial |
