: dm/dt = (minf - m)/tau
: input event adds w to m
: when m = 1, or event makes m >= 1 cell fires
: minf is calculated so that the natural interval between spikes is invl

NEURON {
	ARTIFICIAL_CELL IntervalFire
	RANGE tau, m, invl
	: m plays the role of voltage
}

PARAMETER {
	tau = 5 (ms)   <1e-9,1e9>
	invl = 10 (ms) <1e-9,1e9>
}

ASSIGNED {
	m
	minf
	t0(ms)
}

INITIAL {
	minf = 1/(1 - exp(-invl/tau)) : so natural spike interval is invl
	m = 0
	t0 = t
	net_send(firetime(), 1)
}

FUNCTION M() {
	M = minf + (m - minf)*exp(-(t - t0)/tau)
}

NET_RECEIVE (w) {
	m = M()
	t0 = t
	if (flag == 0) {
		m = m + w
		if (m > 1) {
			m = 0
			net_event(t)
		}
		net_move(t+firetime())
	}else{
		net_event(t)
		m = 0
		net_send(firetime(), 1)
	}
}

FUNCTION firetime()(ms) { : m < 1 and minf > 1
	firetime = tau*log((minf-m)/(minf - 1))
:	printf("firetime=%g\n", firetime)
}