From 1be247657920de839f6cfd9cc06466942675750c Mon Sep 17 00:00:00 2001
From: Alex Janka <alex@alexjanka.com>
Date: Mon, 12 Feb 2024 13:54:03 +1100
Subject: [PATCH] max consecutive errors for tristar

---
 src/charge_controllers/tristar.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/charge_controllers/tristar.rs b/src/charge_controllers/tristar.rs
index f4af5f1..f903de1 100644
--- a/src/charge_controllers/tristar.rs
+++ b/src/charge_controllers/tristar.rs
@@ -47,6 +47,7 @@ pub struct Tristar {
     modbus: Modbus,
     data_in: [u16; RAM_ARRAY_SIZE],
     charge_state_gauges: ChargeStateGauges,
+    consecutive_errors: usize,
 }
 
 #[derive(Default, Debug, Clone, Copy)]
@@ -232,6 +233,8 @@ impl ChargeStateGauges {
     }
 }
 
+const MAX_CONSECUTIVE_ERRORS: usize = 5;
+
 impl Tristar {
     pub fn new(serial_port: String, baud_rate: i32) -> Result<Self, TristarError> {
         let parity = 'N';
@@ -247,6 +250,7 @@ impl Tristar {
             modbus,
             data_in: [0; RAM_ARRAY_SIZE],
             charge_state_gauges,
+            consecutive_errors: 0,
         })
     }
 
@@ -256,6 +260,7 @@ impl Tristar {
             .some_or_print_with("reading tristar state")
             .map(|scaling| TristarState::from_ram(scaling, &self.data_in))
         {
+            self.consecutive_errors = 0;
             BATTERY_VOLTAGE
                 .with_label_values(&[&self.port_name])
                 .set(new_state.battery_voltage);
@@ -292,6 +297,14 @@ impl Tristar {
 
             self.charge_state_gauges.set(new_state.charge_state);
             self.state = new_state;
+        } else {
+            self.consecutive_errors += 1;
+            if self.consecutive_errors >= MAX_CONSECUTIVE_ERRORS {
+                self.modbus.close();
+                if let Err(e) = self.modbus.connect() {
+                    log::error!("error reconnecting to modbus device: {e:?}");
+                }
+            }
         }
     }