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vfd_driver [2016/01/28 09:24] – [micro-controller] kingkevinvfd_driver [2024/01/07 17:49] (current) – external edit 127.0.0.1
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 They each can driver 32 channels (up to 90V). They each can driver 32 channels (up to 90V).
-The VFD segments start already to be visible at 5V, but to get them bright you need higher voltages (I use 60V).+The VFD segments start already to be visible at 5V, but to get them bright you need higher voltages (I use 50V).
 This is particularly important because you have to drive the digits and matrix one after each other. This is particularly important because you have to drive the digits and matrix one after each other.
 If you do it fast enough, thanks to the persistence of vision they will not appear as flickering. If you do it fast enough, thanks to the persistence of vision they will not appear as flickering.
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   - DIN: to shift the data in   - DIN: to shift the data in
   - CLK: clock to shift the data, on the clock rise   - CLK: clock to shift the data, on the clock rise
-  - NLE: enable latch on low+  - #LE: enable latch on low (aka. negative LE, or NLE)
   - STR: strobe the shifted data   - STR: strobe the shifted data
-  - GND: ground+  - AUXconnected to ground when the auxiliary display is present
  
 {{  :vfd_driver:cn1_jumper.jpg?200|CN1 short}} {{  :vfd_driver:cn1_jumper.jpg?200|CN1 short}}
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 The second VFD has 10 digits, and is a copy of the 10 digits from the main VFD (minus comma and underline). The second VFD has 10 digits, and is a copy of the 10 digits from the main VFD (minus comma and underline).
  
-If you don't have the auxiliary VFD connectedthe main VFD will not light up. +The AUX pin of CN2 is shorted to ground when the auxiliary VFD is connected
-To circumvent this protection just short the 3rd right-most to pin with the 2nd right-most bottom pin.+You can use the AUX pin to detect if the auxiliary VFD is present by pulling the pin up and checking if it's low (because shorted to ground)
 +You can also the use AUX pin as second ground pin (i.e. for the VPP power suply). 
 +If the auxiliary VFD is not present, just short the 3rd right-most top pin with the 2nd right-most bottom pin.
  
 ==== segments ==== ==== segments ====
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 The hardware used to control this VFD is a [[stm32f1xx#system_board|STM32F1 development board]], based on a [[http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1031/LN1565/PF164476|STM32F103C8T6]] micro-controller (32-bit ARM Cortex M3, 72MHz). The hardware used to control this VFD is a [[stm32f1xx#system_board|STM32F1 development board]], based on a [[http://www.st.com/web/catalog/mmc/FM141/SC1169/SS1031/LN1565/PF164476|STM32F103C8T6]] micro-controller (32-bit ARM Cortex M3, 72MHz).
  
-The firmware is available [[https://git.cuvoodoo.info/kingkevin/firefly_condcutor|here]].+The firmware is available [[https://git.cuvoodoo.info/firefly_condcutor|here]].
 It : It :
   * starts by testing all segments of the VFD   * starts by testing all segments of the VFD
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 | GPIO | PA4 | 6 | NLE | | GPIO | PA4 | 6 | NLE |
 | GPIO | PA6 | 7 | STR | | GPIO | PA6 | 7 | STR |
-| | | 8 | GND |+| | | 8 | AUX |
  
 The VPP and GND pins to drive the VFD segments are provided using an external power supply. The VPP and GND pins to drive the VFD segments are provided using an external power supply.
 I use a [[http://www.aliexpress.com/item/120W-DC-DC-Boost-Converter-10-32V-to-36-60V-48V-54V-4A-Step-Up-Adjustable/1414029224.html|boost converter]] and set it to 50V. I use a [[http://www.aliexpress.com/item/120W-DC-DC-Boost-Converter-10-32V-to-36-60V-48V-54V-4A-Step-Up-Adjustable/1414029224.html|boost converter]] and set it to 50V.
vfd_driver.1453973054.txt.gz · Last modified: 2024/01/07 17:49 (external edit)