State logger:

• should hava a logic output containing the state
• should trigger a fixed time pulse (that will control communication device's startup)

Second point can be achieved with a 555 timer (ideally in retriggerable mode)

Edge detection : raising or falling

http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0At+304+192+352+192+0+1+-4.622354615205361+0.3772906623776142+100%0Ar+352+176+352+128+0+1000%0AR+352+128+352+96+0+0+40+5+0+0+0.5%0Ag+352+208+352+240+0%0Ar+304+192+272+192+0+1000%0Ar+272+192+272+240+0+10000%0Ag+272+240+272+256+0%0Ac+272+192+224+192+0+0.00001+-4.584972822316002%0As+144+192+224+192+0+1+false%0Ar+224+192+224+128+0+1000%0AR+224+128+224+96+0+0+40+5+0+0+0.5%0Ar+144+192+144+240+0+1000%0Ag+144+240+144+272+0%0Ac+144+192+96+192+0+0.00001+0.9631125498538572%0Ar+96+192+96+240+0+10000%0Ag+96+240+96+272+0%0Ar+96+192+48+192+0+1000%0At+48+192+0+192+0+1+-5.875556863307829+-0.8755568634079877+100%0Ar+0+176+0+128+0+1000%0AR+0+128+0+96+0+0+40+5+0+0+0.5%0Ag+0+208+0+256+0%0A154+112+336+192+336+0+2+0+5%0AI+192+336+240+336+0+0.5+5%0Aw+352+176+416+176+0%0Aw+416+176+416+64+0%0Aw+416+64+-48+64+0%0Aw+-48+64+-48+352+0%0Aw+-48+352+112+352+0%0Aw+0+176+-16+176+0%0Aw+-16+176+-16+320+0%0Aw+-16+320+112+320+0%0AM+240+336+304+336+0+2.5%0Ax+42+38+363+41+4+24+raising%5Csor%5Csfalling%5Csedge%5Csdetector%0Ao+16+64+0+4099+0.0000762939453125+0.00009765625+0+2+16+3%0Ao+4+64+0+4099+1.25+0.0015625+1+2+4+3%0Ao+31+64+0+4610+5+0.1+2+1%0A

Version with square current input

http://www.falstad.com/circuit/circuitjs.html?cct=$+1+0.000005+10.20027730826997+50+5+43%0At+304+192+352+192+0+1+0.5093832671651566+0.6159505635457195+100%0Ar+352+176+352+128+0+1000%0AR+352+128+352+96+0+0+40+5+0+0+0.5%0Ag+352+208+352+240+0%0Ar+304+192+272+192+0+1000%0Ar+272+192+272+240+0+1000%0Ag+272+240+272+256+0%0Ac+272+192+224+192+0+0.00001+-3.5132564496792593%0Ar+224+192+224+128+0+1000%0AR+224+128+224+96+0+0+10+5+0+0+0.5%0Ar+144+192+144+240+0+1000%0Ag+144+240+144+272+0%0Ac+144+192+96+192+0+0.00001+2.4930412306398986%0Ar+96+192+96+240+0+1000%0Ag+96+240+96+272+0%0Ar+96+192+48+192+0+1000%0At+48+192+0+192+0+1+-6.246520615117984+-1.246520615219218+100%0Ar+0+176+0+128+0+1000%0AR+0+128+0+96+0+0+40+5+0+0+0.5%0Ag+0+208+0+256+0%0A154+112+336+192+336+0+2+5+5%0AI+192+336+240+336+0+0.5+5%0Aw+352+176+416+176+0%0Aw+416+176+416+64+0%0Aw+416+64+-48+64+0%0Aw+-48+64+-48+352+0%0Aw+-48+352+112+352+0%0Aw+0+176+-16+176+0%0Aw+-16+176+-16+320+0%0Aw+-16+320+112+320+0%0AM+240+336+304+336+0+2.5%0Ax+42+38+363+41+4+24+raising%5Csor%5Csfalling%5Csedge%5Csdetector%0At+176+128+176+144+0+1+-4.214154487550719+-1.2465206153207053+100%0Aw+160+144+144+192+0%0Aw+192+144+224+192+0%0Ar+176+96+128+96+0+1000%0AR+128+96+64+96+0+2+10+2.5+2.5+0+0.5%0Aw+176+128+176+96+0%0Ao+30+64+0+4610+5+0.1+0+1%0Ao+36+64+0+4099+5+0.003125+1+2+36+3%0A