Alarm Script Recipes
LinkMeter on the RaspberryPi has the ability to fire off user scripts when an alarm goes off. This is in addition to beeping the piezo buzzer. This requires some degree of Linux shell scripting expertise, but using some of these recipes might make things a little easier to understand.
To prevent alarms from turning on and off every time the temperature bounces back and forth across the alarm point there is a hysteresis. This means that the temperature must be outside of the alarm range by more than 1 degree before the alarm will "arm" and be capable of sounding.
Example: Your current temperature is 99.9, and you set the high alarm for 100 at this time. Your alarm is not armed yet and will not arm until is is a degree from the alarm threshold, that is below 99, say 98.9. Even if the temperature rises to 500 the alarm will not go off, as it was never armed.
Now assume the current temperature is 98.9, and you set the high alarm for 100. When it hits 100, the alarm will fire. Even if it drops back below 100, it will keep ringing until silenced. Silencing the alarm only silences the alarm. If the temperature drops below 99 again, the alarm will rearm, and then goes back over 100, the alarm fires again.
| Action | Will Ring Again? | Must Re-Arm? |
|---|---|---|
| Press any button on HeaterMeter unit | Yes | Yes |
| Unplug the alarming probe | Yes | Yes |
| Clicking 'Silence' on web popup | Yes | Yes |
| Setting the trigger point to 0 with al_set | Yes | Yes |
| Open the lid until lid detect activates | Yes | No |
| Un-ticking Alarm 'On' in web config page | No | Yes |
| Setting the trigger point negative with al_set | No | Yes |
| Alarm Action = Silence | Yes | Yes |
| Alarm Action = Disable | No | Yes |
From the LinkMeter configuration website navigate to LinkMeter -> Alarm Scripts. Each script has its own reset / save button! Do not try to edit multiple scripts without saving each in between. The script will only run if the "Execute on alarm" box is checked at the time the alarm goes off (currently ringing alarms have no effect).
First of all, alarm scripts are located in /usr/share/linkmeter/. Do not edit the script named "alarm", as this file will be replaced every time LinkMeter is upgraded and you will lose all changes. Instead, create new files for your scripts. The system first looks for alarm-all, and executes that. If the return value of that script is zero (the default), the system looks for a file named alarm-{probeidx}{alarmtype}. To not execute the alarm-specific script, exit alarm-all with a non-zero return code (e.g. exit 1).
For example if the Pit probe high alarm is going off, it will look for alarm-0H. These files can be a shell scripts, lua scripts, or a regular ARM ELF binaries. These recipes can be used for either an alarm-specific or alarm-all file. The files must be executable, i.e. chmod +x or they will not be run.
There are many variables available to use in your scripts. From a command prompt execute lmclient LMCF for a list. In addition, the alarm system adds al_probe, al_type, al_thresh, pn (alarm probe name), pcurr (alarm probe current value) variables. The al_set function can be used to change the value of the current alarm.
#!/bin/sh
# The first line of any shell script must begin with the above #! line
# Comments begin with #
#!/bin/sh
# Silence this alarm, it will ring again if re-armed
al_set 0
or
#!/bin/sh
# Disable this alarm, it will not ring again
al_set -$al_thresh
Often you want to turn off the Pit when your food is done, this can be done automatically from the Alarms configuration page. However, this is also easily done using lmclient to send a command to HeaterMeter to change the setpoint.
#!/bin/sh
# Lower the setpoint to 100
lmclient LMST,sp,100
You can do more complicated setpoint control with a ramp down script.
#!/bin/sh
case $al_thresh in
180) NEWSP=215; NEWAL=190; ;;
190) NEWSP=205; NEWAL=200; ;;
200) NEWSP=100; NEWAL=0; ;;
esac
lmclient LMST,sp,$NEWSP
al_set $NEWAL
10 degrees too much? That's ok you can ramp down two degrees for every two degrees the meat climbs if you like
#!/bin/sh
if [ "$al_thresh" -gt 199 ] ; then
# done
lmclient LMST,sp,100
exit
fi
NEWSP=$((sp-2))
NEWAL=$((al_thresh+2))
lmclient LMST,sp,$NEWSP
al_set $NEWAL
Often you may not want be notified when the alarm happens but some time after it happens. Cron can be used. Note cron only has per-minute resolution so don't try to make things happen every N seconds. This example calls the alarm-all script 1 hour after the alarm triggers.
#!/bin/sh
# If no parameter, this is a regular alarm
if [ -z "$1" ] ; then
NOW=`date +%s`
# Set target for 1 hour from now 3600=seconds
WHEN=$((NOW+3600))
TARGET=`date -D "%s" -d $WHEN +"%M %H %d %m"`
echo "$TARGET * /usr/share/linkmeter/alarm-all RING${al_probe}" | crontab -
# make sure cron is started, it won't start if there is no crontab at boot
[ -z "$(pidof crond)" ] && /etc/init.d/cron start
else
# This is the cron callback
# Don't fire again
crontab -r
# Do whatever you want here, using another recipe
fi
| Variable | Description |
|---|---|
| al_prep | Preposition describing alarm (above/below) |
| al_probe | Index of ringing alarm (0-3) |
| al_set | FUNCTION change current alarm threshold |
| al_thresh | Threshold of ringing alarm |
| al_type | Type (L/H) of ringing alarm |
| sp | Setpoint |
| pcurr | Current temperature of ringing alarm |
| pcurr0, pcurr1, pcurr2, pcurr3 | Current temperatures |
| pn0, pn1, pn2, pn3 | Probe names |
| Variable | Description |
|---|---|
| fmin, fmax | Blower min/max |
| ip | IP adddress of LinkMeter |
| lb | LCD Backlight |
| lbn | Home Mode |
| ld | Lid detect duration |
| le0, le1, le2, le3 | LED trigger/invert |
| lo | Lid detect offset % |
| oflag | PID output flags |
| palh0, palh1, palh2, palh3 | Alarm high thresholds |
| pall0, pall1, pall2, pall3 | Alarm low thresholds |
| pca0, pca1, pca2, pca3 | Steinheart A coefficients |
| pcb0, pcb1, pcb2, pcb3 | Steinheart B coefficients |
| pcc0, pcc1, pcc2, pcc3 | Steinheart C coefficients |
| pcr0, pcr1, pcr2, pcr3 | Steinheart resistances or thermocouple scale |
| pidb, pidp, pidi, pidd | PID constants |
| po0, po1, po2, po3 | Probe temperature offset (config) |
| prfn0, prfn1, prfn2, prfn3 | Probe RF mapping |
| pt0, pt1, pt2, pt3 | Probe type |
| smin, smax | Servo min/max position (10us) |
| ucid | HeaterMeter version |
The mail transfer agent "msmtp" must be configured before any of the sendmail (email/SMS) commands will work. The web interface for this is under Services -> SMTP. If you prefer editing files, edit /etc/msmtprc with the information appropriate for your mail server
I am no longer able to provide an email relay. HeaterMeter provides a mail gateway for use sending your device to any email server, without degrading your account security in any way. To configure this, use the following settings. All fields listed below are required do not make any changes.
- Server host name or IP: heatermeter.com
- Server port number: 587
- Email 'from' address: alert@heatermeter.com
- Requires authentication: checked
- Account user name: heatermeter
- Account password: Your Raspberry Pi serial number -see below-
- Enable TLS/SSL encryption: checked
- Use STARTTLS: checked
- Verify server certificate: not checked
The account password needs to match your Raspberry Pi's serial number. This can be found under System -> Raspberry Pi -> cpu_serial. The serial/password much include all numbers/letter, do not omit the leading zeros and be sure there is no whitespace in the password.
Account validation occurs by checking your your serial number against the IP address in the HeaterMeter Device Registration database so be sure your HeaterMeter is listed there or the authentication will fail. You may only send messages smaller than 1KB (1024 bytes) and email volume is rate limited to prevent abuse. You may also need to add notify@heatermeter.com to your email address book to prevent SPAM flagging.
Sending messages to gmail and hotmail accounts have been tested working.
account default
host heatermeter.com
port 587
auth on
tls on
tls_certcheck off
tls_starttls on
from notify@heatermeter.com
user heatermeter
password (your Pi serial number)
You will need to turn on Access for less secure apps for your gmail account
account default
host smtp.gmail.com
port 587
auth on
tls on
tls_certcheck off
tls_starttls on
from yourname@gmail.com
user yourname@gmail.com
password password
account default
host smtp.live.com
port 587
tls on
tls_certcheck off
auth on
from yourname@hotmail.com
user yourname@hotmail.com
password password
HeaterMeter supports sending push notifications without configuring MSMTP / email, with a couple of services.
Pushbullet is easiest to configure.
- Create a pushbullet account
- Install the pushbullet app on your phone
- On the pushbullet website, go to Settings -> Account -> Create Access Token
- Paste the Access Token into the field in the HeaterMeter webui under Alarms -> Push Notifications
- Check the "Push" checkbox next to which alarms you want to send push notifications, and Save & Apply
Pushover is only slightly more complicated, but lets you assign this fancy icon to the notifications.
- Create a pushover account
- Install the pushover app on your phone
- On the pushover website, go to Apps & Plugins
- Click the link "Create a New Application / API Token"
- Set name to HeaterMeter (or anything), check the Terms and Conditions checkbox and press "Create Application"
- Copy the "API Token/Key" from pushover into the Application API token/key field in the HeaterMeter webui under Alarms -> Push Notifications
- Back on the pushover website, copy "Your user key" from the main page into the "User key" field in HeaterMeter
- Check the "Push" checkbox next to which alarms you want to send push notifications, and Save & Apply