en:ovi40build:uiboardbuild

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UI V1.7 documents are provided for information only. Please primarily use the V1.8 documents for building the UI V1.8 board.

Please note that the component placement docs are searchable pdf documents. During soldering they can be used to quickly find a component's location by entering the component reference (e.g. “R20”) in pdf search. No need to be concerned to use the V1.7 component placement doc for assembling a V1.8 UI board - V1.7 and V1.7 are quite similar in this respect.

The kit contains UI V1.8 PCB, components in bags and packing list. The display is delivered as assembled and tested unit.

Components in bags (Foto: DL8EBD)
UI V1.8 PCB (Foto: DL8EBD)
Display board (Foto: DL8EBD)

The graphics below - UI V1.7 with 3.2“ Display - give an impression on how the finished V1.8 UI board will look like:

UI Board V1.7 mit 3.2” Display)
UI Board V1.7

Please read Errata carefully

Make sure to read the Errata carefully before starting assembly.

  === IC Device Markings ===

The smaller ICs can be identified by device mark. The following device marks are used:

Typ Device Mark Schematic Purpose
LP5907_Q1 LLVB IC3 LDO 3.3 V
BAV70 A4 D5, D6 Diode
BC857B 3F T3 Transistor
BAS85 Ring = CathodeD7 - D9 Diode

MCU STM32 "Pin 1" marking

Please understand the correct orientation of STM32 MCU Pin 1. There are two markings on the IC. Please not the text printed on MCU to find the correct Pin 1: When reading the text Pin 1 is on bottom left corner.

Orientation of TXCO & MCU (photo DF9EH)
  === STM32F76X_ZIT vs. STM32H743ZIT6 ===

The kit is shipped with STM32F76X_ZIT (“F7”). The just released STM32H743ZIT6 (“H7”) may be used instead. It is suggested to use the F7 for now. Rwason: it is planned to support the H7 in the UHSDR, but no boot loader oder firmware is released for the H7 at the moment.

Comparison of MCUs:

mcHF: OVI40: OVI40 - future:
STM32F407VET6STM32F767ZIT6STM32H743ZIT6
Flash[kB] 500 2048 2048
RAM [kB] 192 512 1024
Clock[MHz] 168 216 400
FPU single double double
Pins 100 144 144
DMIPS 210 462 856

EEPROM IC7 orientation

EEPROM IC7 position (photo DF9EH)

This is where the dot is printed. Also the edge of the case is slanted near the 1-4 pins. See here

Prevent short cut with back up battery holder

One of the connection pins of the battery holder might touch ground connection of a rotary encoder. Make sure to cut this pin flush with PCB surface before soldering - see photo:

Potential Shortcut (photo DF9EH)

Polarised capacitors

Please observe mounting orientation of tantal and electrolytic capacitors. Markings on the capacitors are explained http://elektroniktutor.de/bauteilkunde/c_smdcod.html|here

Mounting locations of switches S7 and S8

Two different mounting locations are provided on the UI PCB for S7 and S8:

  • “mcHF style”: S7 and S8 not line with switches under LCD - they are mounted slightly higher
  • “OVI40 style”: S7 and S8 are mounted in line with the function keys under the LCD

“In line” is the preferred mounting location for S7 and S8.

Temporary Modification: Resistor in parallel to C94

Symptom: In stand-by the current drawn from back-up battery is excessively high. Work-around: Put resistor in parallel to C94. Start with a value of 56k - this seems to work in most cases. If board does not start increase value slightly.

Change brightness of LEDs

Helle LEDS: Mit den Bausatz-Vorwiderständen leuchten die LEDs sehr hell. DF9EH hat die Werte reduziert:

  • R36 auf 22,6k (D1 grün)
  • R37 auf 6,8k (D2 rot)
  • R116 auf 6,8k (D3 blau)


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  • en/ovi40build/uiboardbuild.1517036474.txt.gz
  • Last modified: 27.01.2018 07:01
  • by df9ts_user