CheapPower module

tasmota/berry/modules/cheap_power/autoexec.be

@@ -0,0 +1,11 @@
+var wd = tasmota.wd
+tasmota.add_cmd("CheapPower",
+  def (cmd, idx)
+    import sys
+    var path = sys.path()
+    path.push(wd)
+    import cheap_power
+    path.pop()
+    cheap_power.start(idx)
+  end
+)

tasmota/berry/modules/cheap_power/cheap_power.be

@@ -0,0 +1,154 @@
+import webserver
+import json
+
+var cheap_power = module("cheap_power")
+
+cheap_power.init = def (m)
+class CheapPower
+  var prices # future prices for up to 48 hours
+  var times  # start times of the prices
+  var timeout# timeout until retrying to update prices
+  var chosen # the chosen time slot
+  var channel# the channel to control
+  var tz     # the current time zone offset from UTC
+  static var PAST = -3600 # minimum timer start age
+  static var MULT = .1255 # conversion to ¢/kWh including 25.5% VAT
+  static var PREV = 0, PAUSE = 1, UPDATE = 2, NEXT= 3
+  static var UI = "<table style='width:100%'><tr>"
+    "<td style='width:25%'><button onclick='la(\"&op=0\");'>⏮</button></td>"
+    "<td style='width:25%'><button onclick='la(\"&op=1\");'>⏯</button></td>"
+    "<td style='width:25%'><button onclick='la(\"&op=2\");'>🔄</button></td>"
+    "<td style='width:25%'><button onclick='la(\"&op=3\");'>⏭</button></td>"
+    "</tr></table>"
+  static var URL0 = 'http://sahkotin.fi/prices?start=', URL1 = '&end='
+  static var URLTIME = '%Y-%m-%dT%H:00:00.000Z'
+
+  def init()
+    self.prices = []
+    self.times = []
+  end
+
+  def start(idx)
+    if idx == nil || idx < 1 || idx > tasmota.global.devices_present
+      tasmota.log(f"CheapPower{idx} is not a valid Power output")
+      tasmota.resp_cmnd_failed()
+    else
+      self.channel = idx - 1
+      tasmota.add_driver(self)
+      self.update()
+      tasmota.resp_cmnd_done()
+    end
+  end
+
+  def power(on) tasmota.set_power(self.channel, on) end
+
+  # fetch the prices for the next 24 to 48 hours
+  def update()
+    var wc = webclient()
+    var rtc = tasmota.rtc()
+    self.tz = rtc['timezone'] * 60
+    var now = rtc['utc']
+    var url = self.URL0 +
+      tasmota.strftime(self.URLTIME, now) + self.URL1 +
+      tasmota.strftime(self.URLTIME, now + 172800)
+    wc.begin(url)
+    var rc = wc.GET()
+    if rc == 200
+      var data = json.load(wc.get_string())
+      wc.close()
+      if data data = data.find('prices') end
+      var prices = [], times = []
+      if data
+        for i: data.keys()
+          var datum = data[i]
+          prices.push(self.MULT * datum['value'])
+          times.push(tasmota.strptime(datum['date'],
+                                      '%Y-%m-%dT%H:%M:%S.000Z')['epoch'])
+        end
+        self.timeout = nil
+        self.prices = prices
+        self.times = times
+        self.schedule_chosen(self.find_cheapest(), now, self.PAST)
+        return
+      end
+    else
+      wc.close()
+      print(f'error {rc} for {url}')
+    end
+    # We failed to update the prices. Retry in 1, 2, 4, 8, …, 64 minutes.
+    if !self.timeout
+      self.timeout = 60000
+    elif self.timeout < 3840000
+      self.timeout = self.timeout * 2
+    end
+    tasmota.set_timer(self.timeout, /->self.update())
+  end
+
+  # determine the cheapest slot
+  def find_cheapest()
+    var cheapest, N = size(self.prices)
+    if N
+      cheapest = 0
+      for i: 1..N-1
+        if self.prices[i] < self.prices[cheapest] cheapest = i end
+      end
+    end
+    return cheapest
+  end
+
+  def date_from_now(chosen, now) return self.times[chosen] - now end
+
+  # trigger the timer at the chosen hour
+  def schedule_chosen(chosen, now, old)
+    tasmota.remove_timer('power_on')
+    var d = chosen == nil ? self.PAST : self.date_from_now(chosen, now)
+    if d != old self.power(d > self.PAST && d <= 0) end
+    if d > 0
+      tasmota.set_timer(d * 1000, def() self.power(true) end, 'power_on')
+    elif d <= self.PAST
+      chosen = nil
+    end
+    self.chosen = chosen
+  end
+
+  def web_add_main_button() webserver.content_send(self.UI) end
+
+  def web_sensor()
+    var ch, old = self.PAST, now = tasmota.rtc()['utc']
+    var N = size(self.prices)
+    if N
+      ch = self.chosen
+      if ch != nil && ch < N old = self.date_from_now(ch, now) end
+      while N
+        if self.date_from_now(0, now) > self.PAST break end
+        ch = ch ? ch - 1 : nil
+        self.prices.pop(0)
+        self.times.pop(0)
+        N -= 1
+      end
+    end
+    var op = webserver.has_arg('op') ? int(webserver.arg('op')) : nil
+    if op == self.UPDATE
+      self.update()
+      ch = self.chosen
+    end
+    if !N
+    elif op == self.PAUSE
+      ch = ch == nil ? self.find_cheapest() : nil
+    elif op == self.PREV
+      ch = (!ch ? N : ch) - 1
+    elif op == self.NEXT
+      ch = ch != nil && ch + 1 < N ? ch + 1 : 0
+    end
+    self.schedule_chosen(ch, now, old)
+    var status = ch == nil
+      ? '{s}⭘{m}{e}'
+      : format('{s}⭙ %s{m}%.3g ¢{e}',
+               tasmota.strftime('%Y-%m-%d %H:%M', self.tz + self.times[ch]),
+               self.prices[ch])
+    tasmota.web_send_decimal(status)
+  end
+end
+return CheapPower()
+end
+return cheap_power