updated to run on the pi5

README.md

@@ -76,10 +76,15 @@ sudo apt install nut nut-client nut-server
 Also install RRDTool for the historical data collector:
 
 ```bash
-sudo apt install librrd-dev python3-dev
-python3 -m pip install -r requirements.txt
+sudo apt install librrd-dev python3-dev python3-venv
+cd /opt/ups
+python3 -m venv .venv
+.venv/bin/python -m pip install -r requirements.txt
 ```
 
+The collector uses the virtual environment at `/opt/ups/.venv`. Calling its
+Python executable directly means cron does not need to activate the environment.
+
 Check the NUT version:
 
 ```bash
@@ -538,7 +543,7 @@ The Python collector converts these into numeric values for RRDTool.
 The Python program is:
 
 ```text
-/usr/local/bin/ups_rrd.py
+/opt/ups/ups2rrd.py
 ```
 
 Its job is deliberately simple:
@@ -566,11 +571,12 @@ RRDTool
 PNG graphs
 ```
 
-The script performs three main tasks:
+The script performs four main tasks:
 
 1. Create the RRD database if it doesn't exist
 2. Read the current UPS values
 3. Update the RRD and regenerate the graphs
+4. Generate the HTML dashboard
 
 ---
 
@@ -614,7 +620,7 @@ The corresponding configuration is:
 The cron job runs the Python script every minute:
 
 ```cron
-* * * * * /usr/local/bin/ups_rrd.py >> /var/log/ups_rrd.log 2>&1
+* * * * * /opt/ups/.venv/bin/python /opt/ups/ups2rrd.py >> /var/log/ups_rrd.log 2>&1
 ```
 
 Therefore, approximately one measurement is stored every minute.
@@ -767,6 +773,8 @@ are completely different things.
 The script creates:
 
 ```text
+/var/www/html/ups/index.html
+
 /var/www/html/ups/status-3m.png
 
 /var/www/html/ups/battery-1y.png
@@ -784,6 +792,8 @@ The script creates:
 If `/var/www/html` is served by the web server, these can therefore be viewed as:
 
 ```text
+/ups/
+
 /ups/status-3m.png
 /ups/battery-1y.png
 /ups/battery-5y.png
@@ -794,6 +804,9 @@ If `/var/www/html` is served by the web server, these can therefore be viewed as
 /ups/power-5y.png
 ```
 
+The responsive dashboard groups all graphs on one page and refreshes every
+60 seconds. Clicking a graph opens its full-size PNG.
+
 ---
 
 # 19. Testing the Python program
@@ -801,7 +814,7 @@ If `/var/www/html` is served by the web server, these can therefore be viewed as
 Run it manually:
 
 ```bash
-sudo /usr/local/bin/ups_rrd.py
+sudo /opt/ups/.venv/bin/python /opt/ups/ups2rrd.py
 ```
 
 A successful run should produce something similar to:
@@ -826,12 +839,22 @@ rrdtool lastupdate /var/lib/rrd/bx950mi.rrd
 
 # 20. Checking cron
 
-The cron entry is:
+Install the cron entry in root's crontab because the collector writes to
+`/var/lib/rrd` and `/var/www/html/ups`:
+
+```bash
+sudo crontab -e
+```
+
+Add:
 
 ```cron
-* * * * * /usr/local/bin/ups_rrd.py >> /var/log/ups_rrd.log 2>&1
+* * * * * /opt/ups/.venv/bin/python /opt/ups/ups2rrd.py >> /var/log/ups_rrd.log 2>&1
 ```
 
+There is no need to run `source`, activate the virtual environment, or use a
+wrapper script.
+
 After a few minutes:
 
 ```bash