BPM Generator 20..2400BPM with dividers. www.haraldswerk.de

Motivation

This is the enhanced version of my BPM-Generator in combination with my Clock Divider 2..8 and Clock Divider with primes adapted for Eurorack. The range goes from 20BPM up to 2400BPM. Pulses at 5V/20ms. All 16 outputs are synchronized and work in parallel. Divisions are 1, 2, 3, 4, 5, 6, 7, 8, 11, 13, 17, 19, 23, 29, 31 and 37. You have a start/stop input for the BPM generator and a reset input for the dividers. A 4 digits display shows the current BPM. You can store the latest timing with keypress.

Specs and features

20..2400 BPM
All outputs 5V/20ms
16 outputs
Start/stop input
Divider reset input
4 digit display
Power consumption around 5mA negative rail, 50mA positive rail

Implementation

Schematic

BPM Generator schematic main board 02 — BPM Generator schematic 02: Main board

BPM Generator schematic main board 03 — BPM Generator schematic 03: Main board

Description:

On the control board you see the signal LED's and the in- and outputs, the rotary encoder and the connectors for the display and the main board. On schematic one for the main board you see the microprocessor for generating the main clock. IC3A is the input protection for the start/stop input. IC2A starts or stops the pulses depending on the start/stop input. IC1 decouples the interrupt inputs of the dividers. On schematic two is the microprocessor for the division 2..8 with the output buffers. IC3B is the protection circuit for the reset input of the dividers. Schematic three holds the microprocessor for the division with primes. Not much to see on the schematics, the functionality is in the software.

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Calibration

None

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Building hints

I have put only one ISP interface on the board. So you have to program the microprocessors with in the first socket and move them to the right place. Watch the different fuse settings described in the software listings.