flok
Active member
Hi,
I'm trying to migrate a schematic I made around an arduino (nano) to teensy lc.
This schematic converts a "control voltage" (-5...+5v) to ADC levels (0...5V) and the output of an MCP4725 to that control voltage.
In case anyone is interested how I do that:
to cv: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+188.4969023643409+50+5+50%0AR+256+224+176+128+0+1+9+2.5+2.5+0+0.5%0Ar+256+256+160+256+0+10000%0Ar+240+320+384+320+0+10000%0Aw+256+256+240+320+0%0Aw+384+240+384+320+0%0AR+160+256+64+240+0+0+40+5+0+0+0.5%0Aw+384+240+448+240+0%0Aa+272+240+368+240+9+15+-15+1000000+1.864073282477923+1.8640605639435723+100000%0Aw+272+224+256+224+0%0Aw+272+256+256+256+0%0Aw+368+240+384+240+0%0Ao+0+64+0+4355+5+0.00009765625+0+4+0+3+6+0+6+3%0A
from cv: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0Aa+304+192+416+192+8+5+0+1000000+1.6666666112406259+1.6666666666666665+100000%0Ar+304+112+416+112+0+10000%0Ar+208+208+304+208+0+20000%0Ar+304+208+304+304+0+10000%0Aw+304+112+304+176+0%0Aw+416+112+416+192+0%0Ar+304+176+208+176+0+20000%0AR+208+208+144+208+0+0+40+5+0+0+0.5%0AR+208+176+176+160+0+1+40+5+0+0+0.5%0A368+416+192+480+160+0+0%0Ag+304+304+304+320+0%0Ao+9+64+0+4354+10+6.4+0+2+9+3%0A
My question now is: how do I do that with Teensy 3.3V levels? E.g. 0..3.3v to -5...+5v?
I tried by trial & error and this is what I came up for 0...3 to +/-5 but it results in +/-2.5V instead: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+188.4969023643409+50+5+50%0AR+256+224+176+128+0+1+9+1.65+1.65+0+0.5%0Ar+256+256+160+256+0+20000%0Ar+240+320+384+320+0+10000%0Aw+256+256+240+320+0%0Aw+384+240+384+320+0%0AR+160+256+64+240+0+0+40+5+0+0+0.5%0Aw+384+240+448+240+0%0Aa+272+240+368+240+9+15+-15+1000000+2.2151464197334896+2.2151546469297854+100000%0Aw+272+224+256+224+0%0Aw+272+256+256+256+0%0Aw+368+240+384+240+0%0Ao+0+64+0+4099+5+0.00009765625+0+2+0+3%0Ao+6+64+0+4099+2.5+0.00009765625+1+2+6+3%0A
Any suggestions?
I'm trying to migrate a schematic I made around an arduino (nano) to teensy lc.
This schematic converts a "control voltage" (-5...+5v) to ADC levels (0...5V) and the output of an MCP4725 to that control voltage.
In case anyone is interested how I do that:
to cv: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+188.4969023643409+50+5+50%0AR+256+224+176+128+0+1+9+2.5+2.5+0+0.5%0Ar+256+256+160+256+0+10000%0Ar+240+320+384+320+0+10000%0Aw+256+256+240+320+0%0Aw+384+240+384+320+0%0AR+160+256+64+240+0+0+40+5+0+0+0.5%0Aw+384+240+448+240+0%0Aa+272+240+368+240+9+15+-15+1000000+1.864073282477923+1.8640605639435723+100000%0Aw+272+224+256+224+0%0Aw+272+256+256+256+0%0Aw+368+240+384+240+0%0Ao+0+64+0+4355+5+0.00009765625+0+4+0+3+6+0+6+3%0A
from cv: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0Aa+304+192+416+192+8+5+0+1000000+1.6666666112406259+1.6666666666666665+100000%0Ar+304+112+416+112+0+10000%0Ar+208+208+304+208+0+20000%0Ar+304+208+304+304+0+10000%0Aw+304+112+304+176+0%0Aw+416+112+416+192+0%0Ar+304+176+208+176+0+20000%0AR+208+208+144+208+0+0+40+5+0+0+0.5%0AR+208+176+176+160+0+1+40+5+0+0+0.5%0A368+416+192+480+160+0+0%0Ag+304+304+304+320+0%0Ao+9+64+0+4354+10+6.4+0+2+9+3%0A
My question now is: how do I do that with Teensy 3.3V levels? E.g. 0..3.3v to -5...+5v?
I tried by trial & error and this is what I came up for 0...3 to +/-5 but it results in +/-2.5V instead: https://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+188.4969023643409+50+5+50%0AR+256+224+176+128+0+1+9+1.65+1.65+0+0.5%0Ar+256+256+160+256+0+20000%0Ar+240+320+384+320+0+10000%0Aw+256+256+240+320+0%0Aw+384+240+384+320+0%0AR+160+256+64+240+0+0+40+5+0+0+0.5%0Aw+384+240+448+240+0%0Aa+272+240+368+240+9+15+-15+1000000+2.2151464197334896+2.2151546469297854+100000%0Aw+272+224+256+224+0%0Aw+272+256+256+256+0%0Aw+368+240+384+240+0%0Ao+0+64+0+4099+5+0.00009765625+0+2+0+3%0Ao+6+64+0+4099+2.5+0.00009765625+1+2+6+3%0A
Any suggestions?